A man can row a distance of 6 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?  Choose the correct choice from the following choices
A) 2
B) 8
C) 1
D) 6:41
E) 5
Explanation:   He covered 6 km in 1 hour , so he might cover 20 km in 3 hours 19 minutes.   But he took 10 hours.   He would have saved 10 â€“ 3 hours 19 minutes= 6 hours 41 minutes.   Answer: 6:41
<result>D</result>
A man can row a distance of 6 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?