A train went 300 km from City to city at an average speed of 100 km/h. At what speed did it travel on the way back if/his its average speed for the whole trip was 120 km/h
a)
120 km/h
b)
125 km/h
c)
130 km/h
d)
150 km/h
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Description:
Let,
Way back speed = x
ATQ,
2×x×100/(x+100) = 120
Or, 200x/(x+100) = 120
Or, 200x = 120x+12000
Or, 80x = 12000
Or, x= 150
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