Question

A 52 year-old father has a son and a daughter. The son is twice as old as the daughter. In 4 years the sum of all their ages will be 100. How old are the two siblings now?

Answer 1

24 and 12

Explanation:

s=2d

s+d+52+4(3)=100

Answer 2

son is 24 years old and daughter is 12 years old.

Explanation:

Let the age of son = x years and age of the daughter = y years.

Now for equations

" The son is twice as old as the daughter "

x = 2y -------(1)

"After 4 years sum of all their ages will be 100."

56 + (x+4) + (y+4) = 100

x + y + 64 = 100

x + y = 100 - 64 = 36 ----------(2)

Now we substitute the values of x from equation (1) to (2)

2y + y = 36

3y = 36

y = 12

Now from equation (1)

x = 2 × 12

x = 24 years

Therefore, son is 24 years old and daughter is 12 years old.