Frank is 15 year younger than John.In 5 years,John will be twice as old as Frank.How old Frank will be next four years?

Question

A and B are friends and B is 2 years younger than A. A’s father D is twice as old as A and B is twice as his sister C. The age of D and C differ by 40 years. What are the ages of ‘A’ and ‘B’?

Answer 1

Today Frank's age = x and John's age = x+15

and after 5 years, john will be twice of Frank,
i.e. 2*(x+5)= (x+15+5)
solving this,
we get x = 10 , which is todays age of Frank.
Then after 4 years Frank will 10 + 4 = 14 years old

Answer 2

Frank will be 14 in 4 years