Question

Check whether the following ratios are in proportion or not.
(i) 15 : 30 and 20 : 40
(ii) 25 : 1 and 5 : 20

Answer 1

(i) 15 : 30 and 20 : 40
Product of extremes should be equal to the product of means. Product of extreme $=40\times 15=600$
Product of means $=30\times 20=600$
Product of extreme = Product of means
Hence, the given ratios are in proportion.
(ii) 25 : 1 and 5 : 20
Product of extremes should be equal to the product of means. Product of extreme $=25\times 20=500$
Product of means $=1\times 5=5$
Product of extreme $\ne$ Product of means
Hence, the given ratios are not in proportion.