Identify the graph that best represents the relationship between the number of liters, N, of gasoline purchased at $1.19 a liter, and the total cost of the gasoline C.
The number in each square is obtained by adding the numbers connected to it from the row below.
For example, 3 + 5 = 8
Find the value of X.
The girl is 10% taller than the boy.
In ten years, he will be 50% taller than he is now and the girl will be 10% smaller than the boy.
How much faster will the boy be growing than the girl during these ten years?
90% of 90 girls and 80% of 110 boys have shown up in the concert hall on time.
How many children are late?
In Morse code, each symbol is either a dot or a dash.
What is the best estimate of the average number of symbols in the set shown at the right?
92% of 900 employees of a company arrive at the workplace on time on Friday.
There are 500 female employees in the company and 94% of them have arrived at the workplace this Friday on time.
What is the percentage of the men who are late?
(1 x 105) + (2 x 104) + (3 x 103) + (4 x 102) + (5 x 101) + (6 x 100) + (7 x 0)
written in standard form?
Find the sum of all the elements of this finite geometric sequence:
1, 2, 4, 8, 16, 32, 64, . . . , 2048.
Two candles are of the same height.
One burns in three hours, while the other burns in five hours.
When is one twice the height of the other?
In Morse code, each symbol is either a dot or a dash.
The Morse code was originally used around 1844 for long distance communication by electrical currents in wires, the telegraph.
How many different sequences of 6 symbols are possible?
You can purchase or rent a car.
The car is available at a rental fee of $250 per day (all inclusive).
Purchasing the car costs you $40,000 for the investment and $50 per day.
After how many days would the cost of renting and purchasing be equal?
Choose the answer without using a calculator.
I multiply together the following numbers:
10, 11, 12, 13, 14,15, 16, 17, 18, 19, 20, and 21
How many zeros are at the end of the product?
A report said that for every 100 babies born in a county, there were 12 more girls than boys.
What is the highest expected number of girls in a class of 25 children?
A grocer divides 171kg of potatoes into 5kg and 2kg bags.
If the grocer always produces twice as many small bags as big bags, how many small bags does he use?
Which number between 40 and 50 can be expressed both as the sum of two consecutive integers and as the sum of three consecutive integers?
Jim paints 1/6 in an hour and John paints 1/4 in an hour.
How much time will it take them to paint the fence if they both work together?
A theater sells 150 tickets for a total of $2010.
Children's tickets are sold for half-price, $10.
How many half-price tickets were sold?
A driver's odometer reads 0515 km and the clock reads 05:15 before leaving on a trip.
At the end of the trip, the odometer reads 1505 km and the clock 15:05.
Estimate the average speed of the car.
There is an equal number of boys and girls.
Share $10 among them so that each girl gets $1 more than each boy.
How much does each girl get?
A tennis ball keeps on bouncing back to half of the height from which it is dropped.
Calculate the fraction of its original height that the ball will bounce after it is dropped and it has bounced five times?
In a summer camp, the ratio of people was 11 : 12 : 15 for instructors, boys, and girls.
Calculate how many girls were there if the total number of people was 798.
If 300 people occupy 5/7 of the seats in a concert hall, how many people would occupy 95 percent of the seats in the hall?
Brad has as many sisters as brothers.
His sister Sue has twice as many brothers than sisters.
How many children are there in the family?
The King of a far away land needs to adjust the temperature of the shower all by himself. The inconsiderate servant who normally performs this duty has broken his leg and is therefore unavailable. (The King has failed to realise that kicking the servant caused the servant to trip, breaking his leg because of the fall!)
The King requires a flow rate of 4 liters per minute of 40°C water to be derived from two calibrated hot and cold water taps. The cold water is at 10°C and the hot water is at 50°C. The mixing unit does not change the calibration of the taps or allow heat to be lost from the water.
What settings are required on the taps?
The problem was suggested by Leslie Green
Positive integers a, b, c, and d are such that
a + b + c + d = 20
Find the maximum possible value of their product.
A bottle that fully contains juice weighs 1000 grams.
The bottle with half of the juice weighs 600 grams.
What is the weight of the empty bottle?
Gerry has some candy and Jane has some candy. Gerry gives Jane one of his candies. She now has twice as much as he. She gives Gerry one candy back. They now have the same amount.
How many candies do they have?
It usually takes a man several hours to walk from a railway station to his home.
If he traveled 20% slower than normal, he would arrive one hour too late.
How many hours does he normally walk?
Gerry and Jane bought tickets for a rock concert for them and their friends.
They had the same amount of money at the beginning and exchanged by SMS.
How much does a ticket cost?
Jane hung t-shirts and socks on a clothing line so that a t-shirt is always between any pairs of socks.
How many t-shirts are there on the line if there are 29 pieces of clothing?
A Swiss post office is selling local stamps and European stamps in a book costing 15 Swiss francs.
If a local stamp is 100 centimes = 1 Swiss franc and a European stamp is 130 centimes = 1.3 Swiss francs, how many stamps are there in the book?
Alex and Bob each want to buy the same log. But Alex is $17 short and Bob is $3 short.
How much more money does Bob have than his friend?
If Alex stands on a bench and Evguenia stands on the ground, then he is 40 cm taller than the girl.
If Evguenia stands on the same bench and Alex is on the ground, then she is one metre taller than the boy.
How high is the bench?
Two hundred liters of juice are stored in 260 bottles.
Some of them have a volume of 1 liter, the others have a volume of 0.7 liters.
How many 1-liter bottles were used?
Leslie Green asks:
Mary is half as old as the younger of her two brothers. In 10 years time she will be as old as her younger brother is now.
How old will the younger brother be in 10 years time?
Jane said to Gerry 'If you give me two goldfish, then we will have an equal number of fish. If you give me one fish, then you will have double the number I have!'
What was the total number of fish they had?
Jane and Gerry left their home at the same time and drove to the same sea-side resort.
Gerry drove at a speed of 55 miles per hour.
Jane drove at a speed of 44 miles per hour.
Gerry reached the resort 0.5 hours earlier than Jane.
What is the distance between their home and the resort?
Running the cold water tap fills a bathtub in 15 minutes, while running the hot water tap fills it in 20 minutes.
If the plug is pulled out when the tub is full, it take 12 minutes to empty.
How long does it take to fill the bathtub with both taps running and the plug out?
Leslie Green asks:
In mathematical language, a function can be considered as a rule to transform something into something else. The inverse function will then change it back again.
If the function gives one over the input, what is the inverse function?
At one moment of a dance club performance 2/3 of the boys are dancing tango with 3/4 of the girls.
If there are 34 club members present, how many of them are boys?
The tango is danced in pairs, each consisting of one boy and one girl.
Two trains, initially 400 miles apart, travel towards each other at constant speed, and pass after 4 hours.
If one is travelling 8 miles per hour faster than the other, what is its speed?
Gerry leaves his house a quarter of an hour after Jane.
If he runs three times faster than Jane walks, how long will it take him to catch up to her?
John burns 600 calories bicycling an hour and successfully recovers three quarters of them eating a hamburger after the exercise.
He is not happy with the results.
He decides to cycle more time and still eat only one hamburger.
How much time does he need to cycle to reach his goal of burning 1,000 calories?
In Healthy Drink city, at the last Mayor’s election 100 votes were polled.
The Apple Juice Party candidate was elected by a majority of 3 over the Spring Water Party candidate, by 4 over Green Tea Party candidate, and by 9 over Cow Milk Party candidate.
How many votes were polled for the winner?