A man can row a distance of 5 km in 60 min with the help of the tide. The direction of the tide reverses with the same speed. Now he travels a further 20 km in 10 hours. How much time he would have saved if the direction of tide has not changed? Select the correct option
A) 2 B) 8 C) 1 D) 6 E) 5
Explanation:   He covered 5 km in 1 hour , so he might cover 20 km in 4 hours.   But he took 10 hours.   He would have saved 10 – 4 = 6 hours.   Answer: 6
<result>D</result>
A man can row a distance of 5 km in 60 min with the help of the tide. The direction of the tide reverses with the same speed. Now he travels a further 20 km in 10 hours. How much time he would have saved if the direction of tide has not changed?