Question

Father said to daughter when i was in your age you were 4 years old but then you will be in my age i would be 79 years old then what is the present age of father and daughter

Answer 1

Let the current age of the father be X and that of the daughter be Y.

When father was Y the daughter was 4 years.

Their age difference is the same for all ages.

(Y - 4) years.

(X - Y) years

X - Y = Y - 4

-2Y = - 4 - X

2Y = X + 4

Y = 0.5X + 2

The current age of the daughter is : 0.5X + 2

Their age difference is :

X - 0.5X - 2 = 0.5X - 2

When the father is 79 the daughter is X

Their age difference is :

79 - X = 0.5 X - 2

81 = 1.5 X

X = 81/1.5

X = 54

The current age of the daughter is :

0.5 × 54 + 2 = 29

Present age of the :

Father : 54

Daughter : 29