If a boat is rowed downstream for 200 km in 10 hours and upstream for 96 km in 12 hours, what is the speed of the boat and the river?  Choices:
A) 14 , 18
B) 14 , 6
C) 14 , 14
D) 6 , 6
E) 14 , 10

Rationale: "explanation : if x : speed of boats man in still water y : speed of the river downstream speed ( ds ) = x + y upstream speed ( us ) = x â € “ y x = ( ds + us ) / 2 y = ( ds â € “ us ) / 2 in the above problem ds = 20 ; us = 8 x = ( 20 + 8 ) / 2 = 28 / 2 = 14 km / hr y = ( 20 - 8 ) / 2 = 12 / 2 = 6 km / hr answer : b"
Answer: B