The setupin the post by @josgarithmetic is INCORRECT. The correct setup is THIS system of two equations To solve the system, substitute my first equation to the second equation to get (g-10) + 7 = 10 + . Next, multiply both sides by 2 and simplify, step by step 2*(g-10) + 14 = 20 + (g+7) 2g - 20 + 14 = 20 + g + 7 2g - 6 = g + 27 2g - g = 27 + 6 g = 33. Thus Greg is 33 years old. ANSWER Then Paula is 33-10 = 23 years old. ANSWER