Speed Time & Distance Question Answers

Speed, Time and Distance - Quant/Math - CAT 2008

Question 4 the day: April 22, 2003

The question for the day is from the topic of Speed, Time and Distance.

The speed of a motor boat itself is 20 km/h and the rate of flow of the river is 4 km/h. Moving with the stream the boat went 120 km. What distance will the boat cover during the same time going against the stream?

(1)	80 km			(2)	180 km
(3)	60 km			(4)	100 km

Correct Answer - (1)

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Solution:


Let the distance to be covered by the boat when it is travelling against the stream be x.

The boat goes down the river at a speed of 20 + 4 = 24 km/h and up the river at a speed of 20 � 4 = 16 km/h.

Since the time taken is same 120/24 = x/16

Therefore, x = 80 km.