distance = rate x time

at 80 km/hr

d = 80t

at 64 km/hr

d = 64(t + 1/6) time plus 10 minutes or 1/6 of an hour

80t = 64(t + 1/6) distances are equal

80t = 64t + 32/3 distributed

16t = 32/3 subtracted 64t

t = 2/3 divided by 16

2/3 of an hour is 40 minutes

Add 40 minutes onto 6:50 am

He is supposed to arrive at 7:30 am

~Captain Smart~

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