Eight friends shared 3 seats at a computer gaming station. At any time, exactly 3 friends were seated and playing. Each friend used a seat for 90 minutes.
- Find the total number of minutes that all 8 friends spent in a seat.
- Hence find how long the gaming station was in use, in hours.
Need a hint?
Work out the total minutes all 8 friends sat down first. Then think about how many seats were being used at the same time.
Worked answer
- (a) Total seat time = 8 × 90 = 720 minutes.
- (b) At any time 3 friends were seated, so the 720 seat-minutes were shared by 3 seats at once.
- (b) Time in use = 720 ÷ 3 = 240 minutes.
- (b) 240 minutes = 4 hours.
Answer: 4 hours
The mistake this question tests
Habit
Minutes and hours in rate
Pupils multiply 8 × 90 and stop there, or divide 90 by 3, forgetting that the 720 seat-minutes are shared across the 3 seats.
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