ID 598

The ratio of goats to tigers in a zoo is 3:2.

There are a total of 100 animals in the zoo.

10% of the animals are goats and tigers.

How many goats are in the zoo?

ID 599

Anna spent $9.90 on groceries. She bought three liters of milk and 24 cereal bars.

Three cereal bars cost the same as one liter of milk.

How much does one cereal bar cost?

ID 606

Which statement is INCORRECT?

Here,

'even' is an even number;

'odd' is an odd number;

{Evens} = 2Z = {..., -6, -4, -2, 0, 2, 4, 6, ...},

{Odds} = 2Z + 1 = {..., -5, -3, -1, 1, 3, 5, ...}.

ID 613

Ten men met at a conference.

Each man shook hands with each of the other men exactly once.

How many handshakes took place?

ID 633

ID 644

For every birthday, John's parents put as many dollars in a piggy bank as his age in years.

There are $105 total in the piggy bank.

How old is he?

ID 649

The product of three consecutive whole numbers is 999,900.

What is the smallest of the three numbers?

ID 651

Three boys, A, B, and C, are at the corners of a rectangular field.

At which point should the boys meet so that the sum of the distances they walk to that point is minimized?

ID 653

Eugenia, the magician, receives a 50% discount every time she asks for the price.

She bought a $100 puppy for less than $1.

How many times did she ask for the price?

ID 660

The picture shows two dice with faces numbered 1 through 6.

Six faces are visible.

How many dots are NOT visible in the picture?

ID 662

Find the average of the numbers

7 77 777 7777 77777 777777 7777777

Which is the best estimate of the average?

ID 663

A melon slice weighs 5kg, and 95% of the weight is from water.

After lying in the sun, the water makes up 75% of the weight.

Estimate the new weight of the slice slice in kg.

ID 672

Four friends tried to guess the number of sheep in a flock.

Alex guessed 21,

Bob guessed 26,

Chris guessed 20, and

Daniel guessed 21.

Two were wrong by 2, and two were wrong by 3.

How many sheep were in the flock?

ID 677

Ninety-nine people stand in a line (queue) to buy tickets to a match.

There are enough tickets for each person to purchase two tickets.

Each person in the beginning of the line buys three tickets until there are none left.

How many people do not receive any tickets?

ID 678

ID 1060

ID 1204

If nine hens can lay six eggs in two days, how many hens would be needed to lay 24 eggs in three days?

ID 1305

What is the lowest number of chain links that must be opened to join the pieces on the right into a circular chain?

ID 1306

ID 1427

ID 1428

ID 1505

Tree diagrams present the hierarchical structure of schools or companies.

Which diagram has the smallest number of hierarchical levels?

ID 1517

A dragon drank 1/5 of the water in a lake.

After a break, he drank 1/4 of the remaining water.

After another break, he drank 1/3 of the remaining water.

After a final break, he drank 1/2 of the remaining water.

How much water is left in the lake, compared with the initial amount?

ID 1612

ID 1622

ID 1623

A banker forgets which key fits in which of three keyholes.

What is the minimum number of trials to identify which key is meant for each lock?

ID 1641

It usually takes a man several hours to walk from a railway station to his home.

If he traveled 20% faster than normal, he would arrive one hour too early.

If he traveled 20% slower than normal, he would arrive one hour too late.

How many hours does he normally walk?

ID 1695

Anna ran in the north direction at a speed of 8 km/h, Bobby ran east at a speed of 14 km/h, and their dog, Rex, was running between them at a speed of 20 km/h.

How far did the dog travel in one hour?

ID 1706

ID 1783

After a gun is fired in a saloon, 75% of the cowboys have a wounded ear, 80% have a wounded eye, 85% have a wounded arm, and 90% have a wounded leg.

What is the greatest percentage possible of cowboys who do not have any wounds?

ID 1856

I want to move just one matchstick to make the phrase correct.

From which part will I take the matchstick?

ID 1898

ID 1932

I can buy Swiss cheese in boxes of 250 grams, 450 grams, 650 grams, and 850 grams.

What is the smallest number of boxes I will buy if I want exactly 5 kilograms?

ID 1958

ID 1969

John answers 25 multiple-choice questions and receives a zero score.

Each correct answer is worth 3 points.

Two points are deducted for each incorrect answer.

How many questions does he get correctly?

ID 1971

ID 1983

Several students want to rent a car for the next weekend.

If each contributes $12, they lack $4.

If each contributes $14, they have an extra $4.

How many students are there?

ID 1987

ID 1992

John can eat a pizza in 4 minutes.

Jim can eat a pizza in 5 minutes.

Their grandfather can eat a pizza in 20 minutes.

If two boys and their grandfather all start eating the same pizza at the same time, how many seconds does it take them to finish the pizza?

ID 2005

Construction work commenced on both sides of a 450 meter tunnel.

If a boring machine cuts through chalk marl at a rate of 4 meters per day and another machine cuts through at 5 meters per day, what is the difference between the distances made by the two machines?

ID 2008

ID 2009

ID 2035

Bryan went for a haircut yesterday.

He has 120000 strands of hair and it took 12 minutes to cut all his hairs.

His barber charges $180 per hour.

How much does it cost to cut 1 strand of hair?

ID 2049

Three ducks and four ducklings weigh 3.4kg.

Four ducks and three ducklings weigh 4.3kg.

If all ducks weigh the same and all ducklings weigh the same, what is the weight of a duckling?

ID 2071

The Ancient Olympic Games were held every four years.

They already existed at the time of Homer in 776 BC.

A Roman emperor banned the games in 393 AD.

How many Ancient Olympic Games were held?

ID 2154

Large individual letters are differently priced.

The letters in the word SPRING cost $19.

The letters in the word SUMMER cost $20.

The letters in the word AUTUMN cost $21.

The letters in the word WINTER cost $20.

How much would the letters in the word SEASONS cost?

There is insufficient information to solve this problem.

Elaborate the simplest assumption which gives one of the answers given.

ID 2164

The figure shows the number of people required for the activities of a project and the number of people available in the company.

When must the project manager hire the largest number of additional personnel?

ID 2218

Logic riddle

This occurs once in every second, once in every hour, and twice every afternoon.

How often does it occur every month?

ID 2222

Use all the digits from one to nine and any combination of plus signs and minus signs to obtain 111.

What is the minimum number of plus signs you can use?

ID 2264

Ninety percent of apples in a box and ninety percent of an apple cost the same as all apples in the box.

How many apples are there in the box?

ID 2294

A city hall contains 280 seats. Ninety percent were full and 3/7 of the audience were male.

How many were female?

ID 2938

The mass of Earth is 5.9742 x 10^{24}kg,

the mass of Venus is 4.8685 x 10^{24}kg.

The mass of Mars 6.4185 x 10^{23}kg.

The mass of Moon is 7.3477 x 10^{22}kg

What is smallest mass from the following?

ID 2941

The total weight of Bob and his sister Anna is 151 kilograms. Bob's weight is 1 kilogram more than twice Anna's weight.

What is Anna's weight?

ID 2959

Alex, Bill, and Craig weigh a combined 111 kilograms.

Alex weighs 44 kilograms and Bill weighs seven-eighths of Alex's weight.

What is Craig's weight in kilograms?

ID 2967

ID 2968

A letter in the English alphabet has four times as many letters before it as after it.

Find the letter.

ID 2969

The sum of five consecutive numbers is 2010.

What is the sum of all the digits of these five numbers?

ID 2972

14 students are evenly spaced on the circumference of a big circle.

They are numbered from 1 to 14.

Which number is opposite 10?

ID 2973

22 students are evenly spaced on the circumference of a big circle.

They are numbered from 1 to 22.

Which number is opposite 17?

ID 2988

A river boat travels 4 km in 10 minutes with the current and 1 km in 15 minutes against the current.

Determine the speed of the boat.

ID 2989

ID 2992

Three boys put $550, $550, and $555 in a piggy bank.

Bill is 10% taller than Alex.

Craig is 10% taller than Bill.

How should the money be split if it is distributed as a ratio that is proportional to the children' heights?

ID 2993

Alex paints twice as fast as Bill and three times as fast as Craig.

It takes them 48 minutes to paint a fence.

How long would it take Alex if he works alone?

ID 3038

For every birthday, John's parents put as many dollars in a piggy bank as his age in years.

There are $136 total in the piggy bank.

How old is he?

ID 3048

A melon slice weighs 5kg, and 90% of the weight is from water.

After lying in the sun, the water makes up 75% of the weight.

Estimate the new weight of the slice in kg.

ID 3066

ID 3067

Tim is building two hamster cages in the shape of rectangular prisms. The first cage is 44 cm long, 33 cm wide and 33 cm high. The second cage has the same width, but is 20% longer and higher.

What is the difference between the volumes of the cages?

ID 3075

ID 3077

Pipe 1 can empty a full tank in 1 hour. Pipe 2 can empty the tank in 2 hours.

If both pipes are used to empty the tank, how long will it takes to empty the tank?

ID 3081

The number of strawberry cones sold at an ice cream store was 1 more than 3 times the number of vanilla cones sold.

A total of 301 cones were sold.

How many vanilla cones were sold?

ID 3083

Alex needs six tacks to fix two rectangular pictures because he can overlap the pictures.

What is the least number of tacks he needs to tack 120 pictures?

ID 3084

Water flows through two pipes from F to G.

As shown, there are four taps, A, B, C, and D, which can be opened or closed.

What is the most probable if we randomly set all taps?

ID 3085

There is a set of 10 numbers. Five numbers are selected from the set and multiplied together.

The remaining five numbers are also multiplied together. These two numbers are then added.

Find the maximum possible result.

ID 3086

John's dad pays him 70 cents for each correct answer he provides in his math homework and fines him 30 cents for each incorrect answer.

Today, John received $15 after completing 50 problems.

How many problems did John answer correctly?

ID 3097

ID 3098

It takes 2 cards to build a single-storey card house.

It takes 7 cards to build a 2-storey card house.

It takes 15 cards to build a 3-storey card house.

How many stories can you build with 80 cards?

ID 3100

It takes Alex 40 minutes to paint a fence while it takes Bill 1 hour to paint the same fence.

How long would it have taken if they worked together?

ID 3101

There are 30 boys and 60 girls in Funnytown.

There are 70 men and 40 women in Funnytown.

What is the percentage of boys in the town?

ID 3189

Six post office employees are working today.

It takes one employee one minute to serve one person.

How long would you have to wait in the line if you hold number 201?

ID 3222

Anna had an average score of 90 on her first nine tests.

Her average after all ten tests was 88.

What was the score on her last test?

ID 3245

There are 100 rabbits in Funnytown.

The population of rabbits in Funnytown doubles every 8 months.

How long ago was the population of rabbits less than ten?

ID 3264

Each child in a family has at least 1 brother and 3 sisters.

What is the smallest number of children their parents might have?

ID 3317

The time on a digital clock reads 9:43.

What is the shortest length of time, in minutes, until all of these digits appear again?

ID 3325

Juice is poured from a full 1 L bottle into an empty glass until both the glass and the bottle are 90% full.

What is the volume of the glass?

ID 3362

Mrs. Smith has 80 birds: geese, hens and ducks.

The ratio of geese to hens is 1:3.

60% of the birds are ducks.

How many geese does Mrs. Smith have?

ID 3387

It takes six people 36 hours to paint a house.

How long would it take to paint the house if three people were added in the middle of the project?

ID 3397

ID 3409

Swiss trains leave from Zurich for Geneva every hour.

The trip takes three hours.

Each train returns back without any delay.

How many trains are needed to cover a period of twenty-four hours if there are no trains between 1:00 am and 4:00 am?

ID 3410

A cube consists of small black and white cubes.

Two small cubes of the same color never share a common face.

How many more black cubes are there?

ID 3413

A number is said to be perfect if it is equal to the sum of its divisors.

For example, 28 is a perfect number:

1 + 2 + 4 + 7 + 14 = 28

What is the perfect number that is smaller than 28?

ID 3414

Nine students travel in a car.

They speak English, French and Spanish.

Everybody speaks two languages.

Four students speak French.

Five students speak Spanish.

How many students speak English?

ID 3430

Two hundred employees work for company XYZ, where the ratio of men to women is 11 to 9.

If 60 men leave the company and 10 women are hired, what is the new ratio of men to women?

ID 3455

Four sisters are all 3 years apart in age.

The total of their ages is equal to 30 years.

How old is the eldest sister?

ID 3460

A flower shopkeeper works 6 days per week and sells four times more flowers on Friday and Saturday than the other days. How much does she sell on Friday if she earns $6,000 in flower sales every week.

ID 3489

Eight people pay $7.50 each for a meal in a restaurant.

They leave a 10% tip for the waiter.

How much change do they receive from 4 $20 notes?

The photograph courtesy of Roland Sauter

ID 3494

ID 3595

A non-stop train leaves Zurich for Bern at 58 miles per hour and another non-stop train leaves Bern for Zurich at 62 miles per hour.

How far apart are the trains three minutes before they pass each other?

ID 3600

ID 3612

ID 3648

I ride along a long valley by bus and walk back.

The bus speed is 10 miles per hour and I walk at 4 miles per hour.

If I limit the entire trip to seven hours, how far can I ride by bus?

ID 3650

A shopkeeper buys two kinds of cacao beans at $64 and $96 a bag.

He mixes the beans and sells at $96 a bag, making a profit of 20% on the cost.

What is proportion of the different beans in the mix?

ID 3704

You multiply two consecutive integers and the result is 80 greater than one of them.

What is the smallest of these two integers?

ID 3710

ID 3724

Logic puzzle.

A word for a family member is the same spelled forward and backwards.

How many letters does the word have?

ID 3726

Can you predict the score of any match before it begins?

What is the score of England against France tomorrow?

ID 3728

An Honesty shop sells the first candy for 1 Swiss franc and each next candy for 10% less than the previous one.

Which candy costs nothing?

ID 3738

My father was 27 years old and 9 times as old I was many years ago.

Now he is twice as old as I am.

How old is he now?

ID 3763

At a flower shop, a bouquet of five roses costs $5 and a bouquet of nine roses costs $8.

How much money do I need to buy 77 roses?

ID 3785

A truck can transport either 9 bags or 7 wooden boxes.

Yesterday, the truck transferred 74 items and it was full each time.

How many of them were cacao bags?

ID 3787

A car weighs 988kg when empty and 1224kg when John, his sister Jane, and their two parents are inside.

What is the average weight of a member of the family in kg?

ID 3855

Anna has 7 biscuits, Bill has 4, and Cindy has 1.

They share them out equally.

Cindy pays for her biscuits by leaving 9 wafers.

What is the fairest way for Anna and Bill to share out their wafers?

ID 3874

If the green, yellow, and red regions have areas of 12, 9, and 7 square meters, what is the area of the blue region?

ID 3890

ID 3903

ID 4019

Metro Card prices: a single ride is $2.50 and a 7-day Metro Card costs $29.

How many rides per week makes the 7-day Metro Card profitable?

ID 4084

In a county, 40 villages are connected by roads in such a way that three roads lead in and out of each village.

How many roads are there in the county?

ID 4099

When two non-zero integers are added, multiplied, divided, or subtracted, I always receive one of the numbers or 3.

What is the largest number?

ID 4101

ID 4157

Alex is twice as old as Bill was when he weighed 10kg more than Cindy.

How much did Alex weigh at that time if Cindy weighed 25kg and the sum of three weights was 100kg then and it was 6 years ago?

ID 4181

What is the largest result that can be achieved if different letters in the expression

AB6 + BC1

are replaced with different numbers from 0 to 9?

The question is typical for PISA Test.

PISA stands for Programme for International Student Assessment.

ID 4194

Three couples have 81 coins to share equally between them.

How many coins will each husband get if his wife always gets twice as many as he receives?

ID 4279

A class was given a math problem with four options as the answer.

Ten students chose option A,

six students chose option B, and

two students chose option C.

Gerry Geek chose option D.

Five students didn’t answer.

Which option is correct if the teacher said that one twelfth of the class gave the correct answer?

ID 4296

ID 4343

ID 4353

ID 4405

Once upon a time, there were three little pigs - ages 2, 4, and 6 months.

If one was born in January, when was one of his brothers born?

ID 4423

I multiply the ages of three kids and get 48.

If I add their ages, what is the smallest possible sum I might get?

ID 4480

A car traveling with speed 12 meters per second decelerates uniformly until it comes to rest for 4 seconds.

What is the total distance the car travels as it decelerates?

ID 4481

A car traveling with speed 12 meters per second decelerates uniformly until it comes to rest.

It takes 30 meters to stop.

How much time does it take?

ID 4484

Gerry had 24 LEGO bricks and Jane had 6 bricks.

Gerry gave some of his bricks to Jane so that she ended with twice as many bricks as Gerry.

How many bricks did Gerry give to Jane?

ID 4494

ID 4506

It takes 30 seconds to cut the woodblock into three pieces.

How much time does it takes to cut the same block into four pieces?

ID 4599

Gerry and Jane race on a velodrome.

Gerry can ride 11 miles for every 9 miles that Jane rides.

If Jane rode 54 miles today, how far did Gerry ride?

ID 4633

ID 4664

According to research, an average waist circumference of American men is greater than 40 inches (1 meter).

A $1 bill measures 156 mm long and weighs approximately 1 gram.

How many $1 bills are needed to cover the waist?

ID 4665

If you make one word using each letter below only once, what place does the letter **e** take?

**e r t s s s **

ID 4674

ID 4678

Gerry and Jane are flipping dimes.

Each time, they bet $0.10.

At the end, Jane won 30 cents and Gerry won 2 times.

How many games did they play?

ID 4691

ID 4694

Inflation is where the cost of food, goods, and services rises with time.

Governments are happy with a figure in the range of 1 to 4 percent per year.

If there is a 500% inflation in a country how much will a 2-dollar telephone cost in one year?

ID 4751

Today Jane worked 3 hours at the rate of $9.90 per hour.

How much did she earn today if she spent $2 for transport?

ID 4763

Andrew called all the girls in his class.

He called three of them twice, and two of them 3 times.

Each call cost $0.50. His father, being a fair man, insists that Andrew pays the $10 total cost himself.

How many girls are there in Andrew's class?

ID 4831

ID 4886

Two American coins add up to 35 cents but one of them is not a dime.

What is the coin?

Penny = 1 cent.

Nickel = 5 cents.

Dime = 10 cents.

Quarter = 25 cents.

ID 4930

ID 4942

ID 4952

I choose a cube, which is third from the left, fourth from the right, fifth from the bottom, and sixth from the top.

How many cubes are there?

ID 4964

On the train to New York, Jane sat in the second carriage from the front, and Gerry sat in the third carriage from the back.

They saw each other in the windows and noted that there were 4 carriages between them.

How many carriages were there in the train?

ID 4981

Four sisters are all 2 years apart in age and the youngest is 4 years old.

In how many years will the four daughters together be as old as their father, who is 46 now?

ID 4985

Gerry and Jane are on opposite sides of the fountain.

They then start to run round the fountain.

Gerry's speed is 5/4 of Jane's speed.

How many circuits has Gerry completed when he catches up with Jane for the first time?

ID 5004

ID 5090

Jane and Kate are ski racing. They both start at the same place, at the same time, and follow the same path. Jane is traveling at 5 m/s and Kate is traveling at 8 m/s.

How many meters ahead is Kate after a minute?

ID 5097

If we define the 6 letters in the middle of the alphabet as middle letters, what part of the word 'MIDDLE' are middle letters?

ID 5101

ID 5217

Leslie Green asks:

My Interocitor is broken. Fortunately I have replacements for every single part and each part takes the same time to fit as any other. I also know that the designers were so unbelievably clever that it is inconceivable that one faulty part would cause other parts to fail.

The Interocitor has 60 parts, all of which are different, and I can change from one part to another in 10 seconds without even turning the power off (*hot-swappable parts*). I will know that it is working immediately.

What is the minimum time in which I can guarantee to have fixed it?

An interocitor is a fictional multi-functional device that first appeared in the 1949 story "The Alien Machine".

ID 5227

Leslie Green asks:

"Consider which would hurt less if it was accidentally dropped on your foot, a 30kg bag of cacao beans or a 30kg bag of feathers."

ID 5273

There is a fault with the cruise control on Hank's car such that the speed continuously and linearly increases with time.

When he starts off the speed is set to exactly 60 mph. He is driving on a long straight route with the radio on at full blast and he is not paying any attention to his speed. After 3 hours he notices that his speed has now reached 80 mph.

How far did he travel in the first 3 hours?

Author: Leslie Green