Erica is four times as old as Blair. Nicole is three years older than Erica.
The sum of their ages is 21. How old is Erica?  Choose the correct choice: A) 8 B) 18 C) 19 D) 22 E) 29
The problem concerns three ages. Let x equal Blair’s age. Blair’s age: x   Represent the amounts using the same variable. Erica’s age: 4x   Nicole’s age: 4x 3   Write an equation showing the sum equal to 21. x 4x 4x 3 21   Solve the equation. x 4x 4x 3 21   The variable x is equal to 2, but that 9x 3 21   doesn’t answer the question posed in the 9x 18   problem. The problem asks you to find   Erica’s age, which is equal to 4x, or 4(2). x 2   Answer: Erica is 8 years old.   Check: Blair is 2, Erica is 8, and Nicole is 11. The ages total 21.   correct answer 8
<result>A</result>
Erica is four times as old as Blair. Nicole is three years older than Erica.
The sum of their ages is 21. How old is Erica?