Question 1153896
Let Gavin's age be x
Then Fiona's age = x + 7
Then Alex's age = x - 12
Sum of the ages = x + x + 7 + x - 12 = 73 (given)
i.e. 3*x - 5 = 73
i.e. 3*x = 73 + 5 = 78
Solving for x, x = 78 / 3 = 26
So Gavin's age = 26
Fiona's age = 26 + 7 = 33
Alex's age = 26 - 12 = 14
Confirming, 26 +33 + 14 = 73
Youngest person is Alex whose age is <b>14</b>