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? (RSM problem)

Answer 1

Answer:The age of daughter is 12 years  and age of son is 24 years

Step-by-step explanation:

Given :

Present age of father = 52 years

Let the present age of daughter be x

So according to the question son's age is twice that of daughter's

So present age of son =2x

Now after 4 years the sum of their ages = 100

i.e. x+4 + 2x+4 + 52 +4 =100

3x+ 64 = 100

Subtracting both sides by 64 we get

3x + 64 - 64=100 -64

3x = 36

Dividing LHS and RHS by 3 we get

x=12

i.e. Present age of daughter  = x = 12 years

Present age of son = 2x = 2× 12= 24 years

Answer 2

Answer: son 24 daughter 12

100= total years of age of all ppl in 4years but we want their age now

100=(52+4)+(2x+4)+(x+4)

3x=36

x=12

So daughter is 12 and son is 2x or 24

Any questions on how to set this up or how to arrive at the answer, please feel free to ask. Thanks!