Two printers, Cedar and Maple, each print an identical batch of flyers at a constant rate. Cedar completes one batch in 30 minutes, while Maple takes 50 minutes. The faster printer prints 30 flyers more per minute than the slower printer.
- Which printer prints at a faster rate?
- How many flyers does the slower printer print in 4 minutes?
Need a hint?
The rates are in the opposite order to the completion times. Use the 30 flyers per minute difference to find the size of one rate part.
Worked answer
- (a) Both printers print the same number of flyers, so Cedar is faster because it finishes in 30 minutes instead of 50 minutes.
- Printing rates are inversely proportional to completion times, so Cedar : Maple rates = 50 : 30 = 5 : 3.
- The difference in their rates is 5 − 3 = 2 parts, so 1 part = 30 ÷ 2 = 15 flyers per minute.
- Maple, the slower printer, prints at 3 × 15 = 45 flyers per minute.
- In 4 minutes, Maple prints 45 × 4 = 180 flyers.
The mistake this question tests
Minutes and hours in rate
Do not use the 30 flyers per minute as Maple’s rate. It is only the difference between the two rates, so the rates must first be split into ratio parts.
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