Question 1081423
Richard = X [years old]
Father = 3X [3 times Richard's age]
Mother = 3X - 2 [2 years younger than Father]
Sister = X + 1 [one year older than Richard]
The sum of the ages is 103:
X + 3X + 3X - 2 + X + 1 = 103
Now solve for X:
8X - 1 = 103
X = 104/8 = 13
So Richard is 13 years old.  The other ages can be computed from the relationships above.