pushpitkc wrote:

Malcolm's boat moves at 10 miles per hour in still water. He boats for 4 hours down the stream and then for 4 hours up the stream. If the speed of the water current is 6 miles per hour, how far is he from the starting point?

A. 16 miles

B. 24 miles

C. 32 miles

D. 40 miles

E. 48 miles

Source:

Experts GlobalSpeed down the stream \(= 10+6=16\) miles/hour

Hence distance covered down the stream \(= 16*4\) miles

Speed up the stream \(= 10-6=4\) miles/hour

Hence distance covered up the stream \(= 4*4\) miles.

Therefore net distance from the starting point \(= 16*4-4*4=48\) miles

Option

E