Ratio and Proportion
The ratio of boys to girls in a class is 3:5. If there are 40 students in total, how many are boys?
15 boys
Stan weighs 135 pounds plus 2/7 of his own weight. How much does Stan weigh?
Stan weighs 189 pounds.
NO CALCULATOR
Which is larger: 7/15 or 9/20?
7/15 is larger
The average of 5 consecutive integers is 23. What is the largest of the 5 integers?
25
Carol took a test. She got 18 of the first 20 questions correct, but only one-third of the rest of the questions correct. She got 50% of the entire test. How many total questions were on the test?
68 questions
Maria is twice as old as her brother. Four years ago, she was three times as old as he was then.
How old are they now?
Maria is 16
Her brother is 8
What number is 7/12 of the way from -37 to 647 on a number line?
362
5/8 of a batch
A circle and a square have equal perimeters.
Find the ratio of the area of the circle to the area of the square.
(Use pi=3.14)
4:pi or 1.27:1
How much pure acid (100%) must be added to 10 liters of a 30% acid solution to obtain a 50% solution?
4 liters of pure acid
If a number increases by 20% and then decreases by 20%, what is the net change?
4% decrease
A basketball player made 8 of the first 10 free throws, but only 40% of the remaining free throws. If he made 50% of all his free throws, how many free throws did he attempt in total?
40 free throws
Find two positive numbers, a and b, that are in the ratio of 3 to 8 and whose product is 486.
a=13.5 and b=36?
I want to mix pecans worth $11 per pound with walnuts worth $6 per pound to make 15 pounds of a mixture that will be worth $9 per pound. How many pounds of pecans should go into this mixture?
9 pounds of pecans
What is the sum of the first 47 positive odd numbers subtracted from the sum of the first 47 positive even numbers?
47
A two-digit number is 4 times the sum of its digits. If you reverse the digits, the new number is 9 more than the original. What is the original number?
12