A young man is 20years old now. His dad is 40 years old. In how many years will the young man be three-fourths of his fathers age?

Question

It says

Let X = Number Of Years

20 + x = young man's future age

40 + x = father's future age

20 + x = 3/4(40 + x)

Answer 1

The equation they give you, 20 + x = 3/4(40 + x), is the equation you need to solve.

 

And 10 years is not the solution.  In 10 years the you man will be 30, 3/4 of his dad's age now, but his dad will be 50 and so the young man will be 3/5 his age.