For two numbers X and Y, 40% of X is equal to 50% of Y. The average of X and Y is 72 more than Y. Find 30% of
X.

According to the question,  40% of X is equal to 50% of Y. So, 40% of X = 50% of Y. This can be written as: (40X)/(100) = (50Y)/(100) Since 100 is common on both sides, it can be removed. So, 40X = 50Y Now write the ratio of X and Y. X/Y = 50/40 Now simplify 50/40. 50/40 = 5/4 So, X : Y = 5 : 4 Let X = 5x and Y = 4x. The average of X and Y is 72 more than Y. Average of X and Y = (X + Y)/(2) According to the question: (X + Y)/(2) = Y + 72 Put X = 5x and Y = 4x. (5x + 4x)/(2) = 4x + 72 9x/2 = 4x + 72 9x = 8x + 144 9x − 8x = 144 x = 144 Now, X = 5x X = 5 × 144 = 720 We have to find 30% of X. 30% of X = (30 × 720)/(100) 30% of X = 216