SAT Math Multiple Choice Question 497: Answer and Explanation
2. Damien is throwing darts. He has a total of 6 darts to throw. He gets 5 points for each dart that lands in a blue ring and 10 points for each dart that lands in a red ring. If x of his darts land in a blue ring and the rest land in a red ring, which expression represents his total score?
- A. 10x
- B. 10x + 5
- C. 5x + 30
- D. 60 - 5x
Correct Answer: D
Category: Heart of Algebra / Linear Equations
Strategic Advice: The key to answering this question is to determine how many darts land in each color ring. If there are 6 darts total and x land in a blue ring, the rest, or 6 - x, must land in a red ring.
Getting to the Answer: Write the expression in words first: points per blue ring (5) times number of darts in blue ring (x), plus points per red ring (10) times number of darts in red ring (6 - x). Now, translate the words into numbers, variables, and operations: 5x + 10(6 - x). This is not one of the answer choices, so simplify the expression by distributing the 10 and then combining like terms: 5x + 10(6 - x) = 5x + 60 - 10x = 60 - 5x.