Question 282528
Joe is twice as old as sam. sam is 3 times as old as paul.The sum of all the ages is 90 years. how old is sam?

Let x be Paul's age. Then Sam's age is 3*x and Joe is 2*(3*x). 

The sum of their ages then is:

x + 3x + 2*(3*x) = 90

10x = 90
x = 9

Paul is 9 years old. Calculate Joe's and Sam's ages based on x=9.