Algebra Word Problem...

Question

Kevin is three times as old as Bob. Three years ago the sum of their ages was 10. How old is each now? (Hint: Write an expression first for the age of each now and then for the age of each three years ago.)

Answer 1

B=Bob's age

3B=Kevin's age

(B-3)+(3B-3)=10

B-3+3B-3=10

4B-6=10

4B=16

B=4 years old (Bob)

3B=12 (Kevin)

4-3=1

12-3=9

1+9=10