Niharika covers a distance in 30 min , if she drives at a speed of 60 km/h on an average. Find the speed at which she must drive at to reduce the time of the journey by 30%. Choose the most appropriate option.
A) 84.71 kmph.	B) 85.74 kmph.	C) 83.71 kmph.	D) 85.71 kmph.	E) 84.71 kmph.
Given Speed = 60 Kmph.   It means Niharika covered 60 km in 60 min (1 hour). So, in 30 min he will cover 30 km.   30% time reduced = 30 - 30% of 30= 21 min.   Thus, Niharika needs to cover 30 km in 21 min (0.35 hour).   Speed * Time = Distance.   Speed * 0.35 = 30   Speed = 85.71 kmph.   ANSWER : OPTION 85.71 kmph.
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Niharika covers a distance in 30 min , if she drives at a speed of 60 km/h on an average. Find the speed at which she must drive at to reduce the time of the journey by 30%.