Question
The total present ages of 'X', 'Y' and 'Z' is 150 years
and the average of present ages of 'X' and 'Z' is 44 years. 5 years ago, 'Y' was twice as old as 'X'. Find the difference between the ages of 'Y' and 'Z'.Solution
Sum of present ages of 'X' and 'Z' = 44 × 2 = 88 years So, present age of 'Y' = 150 - 88 = 62 years Let the present age of 'X' = x years According to the question, (x - 5) × 2 = 62 - 5 Or, 2x - 10 = 57 So, x = (57 + 10) ÷ 2 = 33.5 So, present age of 'Z' = 88 - 33.5 = 54.5 years So, required difference = 62 - 54.5 = 7.5 years