SAT Math Multiple Choice Question 228: Answer and Explanation
3. Dahlia is competing in a group stair-climbing relay challenge with two of her friends. They will take turns climbing the stairs of two of Metropolis's tallest buildings. The three of them each plan to climb an equal number of stairs, and Dahlia will go first. The first building has s stairs, and the second building has 3,639 stairs. During the race, Dahlia runs out of energy and is only able to complete 75% of her goal. What is the total number of stairs that Dahlia climbs?
Correct Answer: A
A The key to this problem is understanding that the three friends plan to climb an equal number of stairs. Start with the building for which we know the number of stairs. The friends are each planning to climb 3,639 ÷ 3 = 1,213 stairs. Since 1,213 must be a part of the correct answer, eliminate (B) and (D). Given that Dalia will complete only 75% of her goal, Dalia's total must be multiplied by 75% or 0.75. This eliminates (C). The correct answer is (A).