Question 20: The departure schedule of some buses at My Dinh bus station (Hanoi) is shown in the table below. Assume the buses leave at the same time at 10:35. How long will it take for all 3 cars to leave the station at the same time (since the first time)?
The time of the cars leaving the same station at 10:35 minutes at intervals is BC (9, 10, 15)
We have: 9 = 32, 10 = 2.5, 15 = 3.5.
The common and unique factors are 2, 3 and 5
The largest exponent of 2 is 1 .
The largest exponent of 3 is 2
The largest exponent of 5 is 1
⇒ State balance sheet(9, 10, 15) = 2.32.5 = 90
So every 90 minutes, the buses leave at the same time.
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