Subject: mathqa
Question: 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 20 hours . how much time he would have saved if the direction of tide has not changed ?
Option: 
A: 16
B: 8
C: 2
D: 1
Answer: A