Question

frank is 3 times old as ken. frank is 15 years older than eileen, while ken is 1 year younger than eileen. What are thw ages of frank, ken and eileen?

Answer 1

F = 3K
F = E + 15
K = E - 1

You can plug in either 3K or (E+15) for F, so now you've got this equation:

3K = E + 15

We know that Kevin = E - 1, so we plug that in for K:

3(E-1) = E + 15
3E - 3 = E + 15
2E = 18
E = 9 [So, Eileen must be 9]

Plug in 9 for E to find Kevin's age, and then plug in Kevin's age to find Frank's age.