If P is the Peter's age, then (P-7) is the Wendy's age. From the condition, P + (P-7) = 63, 2P = 63 + 7 = 70, P = = 70/2 = 35. ANSWER. Peter is 35 years old.
From the condition, you have these two equations P + W = 63 P - W = 7 Add the equations and see what will happen.