1. A train 100 meters long completely passes a man walking at 6 km/hr in the same direction in 5 seconds and a car travelling in the same direction in 6 seconds. At what speed was the car

travelling? (km/hr = kilometres/hour)

a. 18 km/hr

b. 48 km/hr

c. 24 km/hr

d. 30 km/hr

## EXPLANATION

A train 100 meter long completely passes a man walking in the same direction at 6 km/h in 5 seconds. (x = train)

5 = 100*18 / (x-6)*5

=> 5 = 1800 / (x-6)*5

=> 5 = 1800 / 5x-30

=> 25x – 150 = 1800

=> 25x = 1950

=> x = 78

A car travelling in the same direction in 6 seconds. (y = car)

6 = 100*18 / (x-y)*5

=> 6 = 1800 / (78-y)*5

=> 6 = 1800 / 390-5y

=> 2340 – 30 y = 1800

=> -30y = 1800 – 2340

=> -30y = -540

=> y = 18

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