Question

22 pen are bought for rs 20 and 20 pen sold for rs 22 find the gain %

Answer 1

$22 = 20 \\ 1 = 0.9090 \\ 20 = 22 \\ 1 = 1.1 \\ 0.909 \frac{100}{1.1} = 82.63 \\ 100 - 82.63 = 17.37$