Question

Four years ago Stephanie was 2/3 as old as Alex was then. Four years from now, she will be 4/5 as old as Alex will be. How old are Stephanie and Alex now?

Please let me know how you set up your equation. Thanks

Answer 1

Let the Present age of Alex be 'X'.
and Present age of Stephanie be 'Y'.

According to the question:

(A) 4 years Before,
Stephanie was 2/3 of Alex's then age.

2/3 * (X-4) = (Y-4)
2x-8 = 3y-12

2x-3y = -4 ( Equation 1)

(B) 4 years After
Stephanie will be 4/5 of Alex's then age.

4/5 * (X+4) = (Y+4)
4x+16 = 5y + 20

4x- 5y = 4 ( Equation 2)

Solving Equation 1 and 2 we get:

Present age of Alex= 16 Years
Present age of Stephanie = 12 years