Ratios

Ratios

Simplifying Ratios

Divide by the largest common factor

Multiple Choice

Simplify the ratio 25 : 40

• 5 : 8

• 1 : 5

• 2 : 9

• 1 : 2

Multiple Choice

Simplify the ratio 80 : 30

• 4 : 1

• 8 : 3

• 5 : 2

• 3 : 8

Simplify in the form 1:n

Divide both values by the first number, so that the first number becomes 1

Multiple Choice

Simplify the ratio 3:8 in the form 1:n

• 1 : 8

• 1 : 3.8

• 1 : 2.67

• 1.5 : 4

Multiple Choice

Simplify the ratio 7 : 2 in the form 1:n

• 3.5 : 1

• 1 : 0.29

• 1 : 0.5

• 1 : 2

Finding the missing number in a ratio

Write the numbers underneath each other, and multiply to find the missing value

Multiple Choice

Petra mixes yellow and blue paint in the ratio 4 : 7. She uses 80ml of yellow. How much blue paint does she need?

• 70ml

• 100ml

• 120ml

• 140ml

Multiple Choice

The ratio of men and women is 8 : 11. There are 32 men. How many women are there?

• 33

• 40

• 44

• 22

Multiple Choice

The ratio of cats to dogs is 5 : 8. There are 40 dogs. How many cats are there?

• 64

• 25

• 50

• 20

Sharing in a given ratio

• Add the numbers in the ratio

• Divide the total value by the added ratio

• Multiply this answer by each number in the ratio

Multiple Choice

Share 100euro in the ratio 1 : 4

• 30 and 70

• 20 and 80

• 50 and 50

• 10 and 40

Multiple Choice

Share 45 in the ratio 4 : 5

• 15 and 30

• 40 and 50

• 20 and 25

• 10 and 35

Multiple Choice

Kim and David share 200euro in the ratio 11 : 9. How much do they each get?

• 20 and 90

• 100 and 100

• 22 and 99

• 110 and 90

Multiple Choice

To make a fruit drink, Emma mixes strawberry, pear and banana juice in the ratio 2 : 3 : 4. How much of each ingredient does she need to make 360ml of this fruit drink.

• 120, 120 and 120

• 80, 120 and 160

• 60, 90 and 120

• 50, 110 and 200

Map Ratio

• To write a map ratio, make sure all measurement are in cm

• To change m to cm x100

• To change km to cm x 100 x 1000

Multiple Choice

The scale on a map is 1cm represents 8m. Write this down as a ratio

• 1:8

• 1:800

• 1:800 000

• 1:80 000

Multiple Choice

The scale on a map is 2cm represents 10km. Write this down as a ratio in simplest form.

• 2:100 000

• 1:50 000

• 1:5

• 2:10

Mixed Problems

Open Ended

Simplify the ratio 15 : 40

Open Ended

The ratio of white marbles to black marbles is 5:7. If there are 35 white marbles, how many black marbles are there?

Open Ended

David bakes a cake using flour, sugar and butter in the ratio 6 : 3 : 2. If he uses 600g of flour, how much sugar and butter does he need?

Open Ended

Share 600euro in the ratio 1:2

Open Ended

Elena and James share 450 euro in the ratio 2:7. How much money does each of them get?

Open Ended

The three angles of a triangle are in the ratio 2 : 3 : 4. What is the size of each angle?

Open Ended

The scale on a map is 5cm represents 20km. Write this down as a ratio in simplest form.