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Flashcards · Maths · Ratio and Proportion

Ratio: Simplifying and Sharing

17 cards

  1. What does a ratio of 3 : 5 tell you?

    For every 3 parts of the first quantity there are 5 parts of the second. It does not tell you the total.

  2. Why does the order of a ratio matter?

    Boys to girls 3 : 5 is not the same as girls to boys 3 : 5. Write it in the order the question asks.

  3. How do you simplify a ratio?

    Divide every part by the highest common factor, so \(12 : 18 = 2 : 3\).

  4. How do you simplify \(50\text{ cm} : 2\text{ m}\)?

    Change to the same units first: \(50 : 200 = 1 : 4\).

  5. How do you remove fractions from \(\dfrac{1}{2} : \dfrac{1}{3}\)?

    Multiply both parts by the common denominator, 6, to get \(3 : 2\).

  6. What is the form \(1 : n\)?

    A ratio with the first part 1, found by dividing both parts by the first part: \(4 : 10 = 1 : 2.5\).

  7. What are the three steps for sharing in a ratio?

    Add the parts, divide the total by the number of parts to find one part, then multiply.

  8. Share \(\pounds 60\) in the ratio \(2 : 3\).

    5 parts, one part is \(\pounds 12\), so \(\pounds 24\) and \(\pounds 36\).

  9. Share 240 in the ratio \(3 : 4 : 5\).

    12 parts, one part is 20, so 60, 80 and 100.

  10. In the ratio \(3 : 5\) the smaller part is \(\pounds 18\). What is the larger part?

    One part is \(\pounds 6\), so the larger part is \(\pounds 30\).

  11. In the ratio \(3 : 7\) the difference is \(\pounds 20\). What are the amounts?

    The difference is 4 parts, so one part is \(\pounds 5\) and the amounts are \(\pounds 15\) and \(\pounds 35\).

  12. What fraction of the whole is the first part of \(2 : 3\)?

    \(\dfrac{2}{5}\), because the whole is 5 parts.

  13. If \(\dfrac{1}{4}\) of a class walk, what is the ratio of walkers to the others?

    \(1 : 3\).

  14. What is the difference between a ratio and a fraction?

    A ratio compares part with part, but a fraction compares a part with the whole.

  15. How do you increase 40 in the ratio \(3 : 2\) (Higher tier)?

    Multiply by \(\dfrac{3}{2}\) to get 60.

  16. How do you combine \(a : b = 2 : 3\) and \(b : c = 4 : 5\) (Higher tier)?

    Make \(b\) match using 12: \(8 : 12\) and \(12 : 15\), so \(a : b : c = 8 : 12 : 15\).

  17. How do you check a ratio sharing answer?

    The shares must add up to the total and be in the original ratio.