Jim is 3 times as old as his cousin and the difference in their ages is 18. How old is Jim?

Question

how do i solve this

Answer 1

You have two variables and two equations.

J=3C

J-C=18

 

Can you take it from there?

 

What if you used one equation to make a substitution in the other, so that it only had one variable?

Answer 2

Let cousin's age = x

Let Jim's age = 3x

 

Since the difference between their ages is 18,

 

3x - x = 18

 

 

Solving for x,

 

2x = 18

 

  x = 9

 

 

Cousin's age is 9. Jim's age is 27.