Digital SATMath: Problem-Solving and Data AnalysisMedium
A financial analyst is reviewing a company's sales data. In Q1, the company sold 2,400 units. In Q2, sales increased by 20% compared to Q1. In Q3, sales decreased by 10% compared to Q2. What were the company's sales in Q3?
- A2,880 units
- B2,760 units
- C2,640 units
- D2,592 units
Show answer & explanationAnswer & explanation
Correct answer: D. 2,592 units
Q1 sales: 2,400 units. Q2 sales: 2,400 * (1 + 0.20) = 2,400 * 1.20 = 2,880 units. Q3 sales: 2,880 * (1 - 0.10) = 2,880 * 0.90 = 2,592 units.
Why the other options are wrong
- A. This is the sales figure for Q2, not Q3 (2,400 * 1.20 = 2,880).
- B. This option might arise from applying the 10% decrease to the original Q1 sales (2400 * 0.90 = 2160) or from miscalculating the Q2 increase.
- C. This might result from incorrectly applying the percentages, perhaps by calculating the net percentage change (20% - 10% = 10%) and applying it to Q1 (2400 * 1.10 = 2640).
Successive Percentage Changes
Successive percentage changes involve applying one percentage change, and then applying a second percentage change to the new value, not the original value.
- Each percentage change is calculated on the current value.
- Order of changes matters if the base is different.
- Cannot simply add or subtract percentage changes directly.
Memory trick: Each step's percentage changes the NEW total, not the start.