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Primary 5 · Mathematics · Ratio

Ratio questions for Primary 5 Maths

10 questions to work through online. Answer and you get the working straight away, then a score at the end. No sign-up, and you can retake it as often as you like.

  • Writing a ratio
  • Simplifying a ratio
  • Sharing in a ratio
  • Finding a missing part
  • Equivalent ratios
  • Ratio in a recipe
  • Ratio as a fraction
  • Working backwards
  • Three-part ratio
0 of 10 answered
Question 1 of 10Writing a ratio
There are 12 boys and 20 girls in a class. What is the ratio of boys to girls in its simplest form?
Question 2 of 10Simplifying a ratio
Express 45 : 60 in its simplest form.
Question 3 of 10Sharing in a ratio
$350 is shared between Ann and Ben in the ratio 3 : 4. How much does Ann get?
Question 4 of 10Finding a missing part
The ratio of red beads to blue beads is 5 : 8. There are 120 red beads. How many blue beads are there?
Question 5 of 10Sharing in a ratio
66 sweets are shared between two children in the ratio 4 : 7. How many more sweets does the second child get?
Question 6 of 10Equivalent ratios
Which ratio is equivalent to 2 : 3?
Question 7 of 10Ratio in a recipe
A recipe uses flour and sugar in the ratio 3 : 2. If 900 g of flour is used, how much sugar is needed?
Question 8 of 10Ratio as a fraction
In a box the ratio of pens to pencils is 3 : 5. What fraction of the items in the box are pens?
Question 9 of 10Working backwards
Two numbers are in the ratio 5 : 8. Their difference is 45. What is the larger number?
Question 10 of 10Three-part ratio
$720 is shared among three friends in the ratio 2 : 3 : 4. How much does the friend with the largest share get?
Answers and explanations for all 10 questions

Every answer with the reasoning behind it. Worth reading after you have tried the set — or on its own, if you are a parent marking it.

  1. There are 12 boys and 20 girls in a class. What is the ratio of boys to girls in its simplest form?

    Answer: 3 : 5

    Both 12 and 20 divide by 4: 12 ÷ 4 = 3 and 20 ÷ 4 = 5, giving 3 : 5.

  2. Express 45 : 60 in its simplest form.

    Answer: 3 : 4

    The largest number dividing both 45 and 60 is 15: 45 ÷ 15 = 3 and 60 ÷ 15 = 4, giving 3 : 4.

  3. $350 is shared between Ann and Ben in the ratio 3 : 4. How much does Ann get?

    Answer: $150

    3 + 4 = 7 units, so 1 unit is $350 ÷ 7 = $50, and Ann's 3 units are $150.

  4. The ratio of red beads to blue beads is 5 : 8. There are 120 red beads. How many blue beads are there?

    Answer: 192

    5 units = 120, so 1 unit = 24, and the 8 blue units are 8 × 24 = 192.

  5. 66 sweets are shared between two children in the ratio 4 : 7. How many more sweets does the second child get?

    Answer: 18

    4 + 7 = 11 units, so 1 unit = 6 sweets. The difference is 7 − 4 = 3 units, which is 3 × 6 = 18.

  6. Which ratio is equivalent to 2 : 3?

    Answer: 10 : 15

    Multiply both parts of 2 : 3 by 5 to get 10 : 15.

  7. A recipe uses flour and sugar in the ratio 3 : 2. If 900 g of flour is used, how much sugar is needed?

    Answer: 600 g

    3 units = 900 g, so 1 unit = 300 g, and the 2 units of sugar are 2 × 300 = 600 g.

  8. In a box the ratio of pens to pencils is 3 : 5. What fraction of the items in the box are pens?

    Answer: 3/8

    3 + 5 = 8 units altogether, and the pens are 3 of them, so 3/8.

  9. Two numbers are in the ratio 5 : 8. Their difference is 45. What is the larger number?

    Answer: 120

    The difference is 8 − 5 = 3 units = 45, so 1 unit = 15, and the larger number is 8 × 15 = 120.

  10. $720 is shared among three friends in the ratio 2 : 3 : 4. How much does the friend with the largest share get?

    Answer: $320

    2 + 3 + 4 = 9 units, so 1 unit is $720 ÷ 9 = $80, and 4 units are 4 × $80 = $320.