City corporation recently started a cab service from certain terminal, which runs at a speed of 30 k

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17 Feb 2022 Time Distance & Speed

City corporation recently started a cab service from certain terminal, which runs at a speed of 30 km/h at an interval of 20 minutes each. A woman coming towards terminal observes that she crosses the cab at an interval of 15 minutes. The speed of a woman (in km/h) is

OPtion

1) 10
2) 20
3) 15
4) 12
5) 24
6) 30
7) 18
8) 9
9) 8
10) None of these

Solution

Let the speed of a woman=x km/h, then relative speed=(x+30) km/h
Distance traveled by cab in 20 min = Distance covered by woman at speed of (x+30) in 15 min.
30*(20/60) = (x+30)*(15/60)
10 = (x+30)*(1/4)
x = 10 km/h

Correct Option: 1 Best Solution (2)