In 7 years Deac will be be twice as old as Irina Four years ago he was three times as old as Irina was then How old are each of them now?

Problems like this are straightforward to solve, once you've translated the information supplied into equations.

So: Let Deac and Irina be respectively A and B years old.

From the first bit: A + 7 = 2(B+7) Tidy this up: A + 7 = 2B + 14, and A - 2B = 7

From the second bit: A - 4 = 3(B-4), A - 4 = 3B - 12, and 3B - A = 8

We have to solve the two equations in bold simultaneously, which in this case is nice and easy. Simply adding the two equations together eliminates A: [A - 2B] + (3B - A) = [7] + (8) so B = 15 Having found B, we look back to a previous equation... A - 2B = 7, A - 30 = 7, A = 37 ...to find A.

So, Deac is 37 and Irina is 15.