GRE General TestQuantitative ReasoningMedium
A production line produces 2,400 items per day. Due to an efficiency improvement, the production increases by 10%. The following month, due to a new machine, production increases by an additional 5% of the new amount. What is the total daily production after both improvements?
- A2,772 items
- B2,640 items
- C2,760 items
- D2,880 items
Show answer & explanationAnswer & explanation
Correct answer: A. 2,772 items
This is a successive percentage increase problem. First, calculate the production after the 10% increase. Then, calculate the second 5% increase based on that new amount.
Why the other options are wrong
- B. This is the production after only the first 10% increase.
- C. This calculates the second increase based on the original amount (2400 + 240 + 120 = 2760), not the new amount.
- D. This would be the result if the production increased by a total of 20% (10%+5% of original+5% of original).
Multi-Step Percentage Increase
Multi-step percentage increase involves applying successive percentage increases, where each subsequent increase is calculated based on the *new* amount after the previous increase.
- Each percentage increase is applied sequentially.
- The base for the next percentage calculation changes.
- Can be calculated using multipliers: (1 + % increase as decimal).
Memory trick: Step-by-Step Percent: Calculate the first increase, then use *that new total* for the next!