Nicole is half as old as Donald. The sum of their ages is 72. How old is Nicole in years?

Nicole is half as old as Donald. The sum of their ages is 72. How old is Nicole in years?

Let n be Nicole's age. Let d be Donald's age. We're given two equations:

1. n = 0.5d
2. n + d = 72

Substitute equation (1) into (2):
0.5d + d = 72
1.5d = 72

Typing this equation into the search engine and solving for d, we get:
d = 48