|A) 30||B) 36|
|C) 45||D) 20|
Given that, speed of thief motorcycle is x kmph .
Given that, policemen started chasing him after 4 hours and catches him in 4 hours.
Distance travelled by the thief in 4 + 4 = 8 hours is d = s t
=> d = 8x kms
Distance covered by the police in 4 hours is
D = 4 x 40 = 160 kms
To catch the thief, distance covered by the thief is equal to distance covered by the police .
d = D
d = 8x = 160
x = 160/8 = 20
x = 20 kmph
Hence, the speed of thief's motorcycle is 20 km/hr.