Q1.
Express the following fractions as percentages. (i) 3/5 (ii) 7/14 (iii) 9/20 (iv) 72/150 (v) 1/3 (vi) 5/11
Answer
A fraction is of one unit and a percentage is per 100 units, so multiply each fraction by 100.
(i) 3/5 × 100 = 300/5 = 60%
(ii) 7/14 = 1/2, and 1/2 × 100 = 50%
(iii) 9/20 × 100 = 900/20 = 45%
(iv) 72/150 = 12/25, and 12/25 × 100 = 1200/25 = 48%
(v) 1/3 × 100 = 100/3 = 33.33% (exactly 33⅓%)
(vi) 5/11 × 100 = 500/11 = 45.45% (45.4545… %)
(ii) 7/14 = 1/2, and 1/2 × 100 = 50%
(iii) 9/20 × 100 = 900/20 = 45%
(iv) 72/150 = 12/25, and 12/25 × 100 = 1200/25 = 48%
(v) 1/3 × 100 = 100/3 = 33.33% (exactly 33⅓%)
(vi) 5/11 × 100 = 500/11 = 45.45% (45.4545… %)
Why it happens: Writing 3/5 as a percentage means finding the equivalent fraction with 100 in the denominator: 3/5 = 60/100. Multiplying by 100 does exactly that in one step, because (3/5) × 100 is the numerator that sits over 100.
Check it yourself: (v) and (vi) do not stop. 1/3 and 5/11 have denominators with prime factors other than 2 and 5, so no equivalent fraction of theirs can have denominator 100 — their percentages are non-terminating decimals, and we round.