Nicole is half as old as Donald. The sum of their ages is 72.
How old is Nicole, in years?
Let's assume Nicole's age is x and Donald's age is y.
Given that Nicole is half as old as Donald, we can write the equation: x = (1/2)y
Also, the sum of their ages is 72. So, we can write the equation: x + y = 72
Substituting the value of x from the first equation to the second equation, we get: (1/2)y + y = 72
Multiplying through by 2, we get: y + 2y = 144
Combining like terms, we get: 3y = 144
Dividing both sides by 3, we get: y = 48
Substituting the value of y in the first equation, we get: x = (1/2)*48 = 24
Therefore, Nicole is 24 years old.