Question

Mr. Y is 3 times as old as his doughter . In 15 years time . The sum of their age is 86 . A, find their age now B,how old was Mr. Y when his doughter born

Answer 1

Explanation:

Let x represent Mr Y's current age.

Let y represent the age of his daughter.

Mr. Y is 3 times as old as his daughter. This means that

x = 3y

In 15 years time, the sum of their age is 86. This means that

(x + 15) + (y + 15) = 86

x + y + 30 = 86 - - - - - - - - - -1

Substituting x = 3y into equation 1, it becomes

3y + y + 30 = 86

4y + 30 = 86

4y = 86 - 30 = 56

y = 56/4 = 14

x = 3y = 3 × 14 = 42

Mr Y is 42 years now

His daughter is 14 years now

When his daughter was born, Mr Y was 42 - 14 = 28 years