Bob is twice as old as Henry. The sum of their ages is 42. How old is Henry?

Bob is twice as old as Henry. The sum of their ages is 42. How old is Henry?

Let Bob's age be b. Let Henry's age be h. We're given two equations:

1. b = 2h
2. b + h = 42

Substitute b = 2h in equation 1 into equation 2 for b:
2h + h = 42

To solve for h, we type this equation into our search engine and we get:
h = 14