If a sailer sails 12 km distance within 5 hours against the flow of a river. If he sails 22 km distance in same time along the flow of the river. Then velocity of the river is _______

If a sailer sails 12 km distance within 5 hours against the flow of a

1.	If a sailer sails 12 km distance within 5 hours against the flow of a river. If he sails 22 km distance in same time along the flow of the river. Then velocity of the river is _______
A.	1 km / hour
B.	2 km / hour
C.	1.5 km / hour
D.	2.5 km / hour
Answer» B. 2 km / hour