Ratios Introduction — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. A soccer team won 8 games and lost 12 games. What is the simplest part-to-part ratio of wins to losses?
A) 2:3
B) 3:2
C) 8:20
D) 4:6
8 and 12 share factor 4; dividing gives 2:3, the simplest part-to-part ratio.
2. A box has 6 apples and 9 oranges. What is the part-to-whole ratio of apples to all fruit in simplest form?
A) 6:9
B) 2:5
C) 3:5
D) 2:3
Total fruit is 15 and 6 are apples, so 6:15 simplifies to 2:5.
3. Paint mixes red and yellow in a 4:5 ratio. If you use 20 cups of yellow, how many cups of red do you need?
A) 15
B) 20
C) 16
D) 25
Scaling 4:5 by 4 gives 16:20, so 20 cups yellow needs 16 cups red.
4. In a class of 35, the ratio of boys to girls is 3:4. How many girls are in the class?
A) 15
B) 21
C) 14
D) 20
35 divided by 7 parts is 5 per part; 4 parts of girls gives 20 girls.
Part B: Fill in the Blank
Write the correct answer on each line.
1. A team plays 7 home games and 5 away games; the part-to-part ratio of home to away is 7:5.
Home games are 7 and away games are 5, so the part-to-part ratio is 7:5.
2. A paint mix uses 3:7 red to white; for 21 cups white, you need 9 cups red.
Scaling 3:7 by 3 gives 9:21, so 21 cups white needs 9 cups red.
3. A bag has 4 black and 6 white balls; the part-to-whole ratio of black to all in simplest form is 2:5.
Total balls is 10 and 4 are black; 4:10 simplifies to 2:5.
4. In a class of 24, the ratio of boys to girls is 1:2; the number of girls is 16.
24 divided by 3 parts is 8 per part; 2 parts of girls gives 16 girls.
5. If a recipe uses sugar and flour in a 2:5 ratio and you use 20 cups flour, you need 8 cups sugar.
Scaling 2:5 by 4 gives 8:20, so 20 cups flour needs 8 cups sugar.