A boat can travel with a speed of 24 km/hr in still water. If the speed of the stream is 4 km/hr, find the time taken by the boat to go 112 km downstream  Choose the correct choice from the following answers:
A) 3 hours
B) 4 hours
C) 5 hours
D) 6 hours
E) 7 hours

Rationale: "explanation : speed of the boat in still water = 24 km / hr speed of the stream = 4 km / hr speed downstream = ( 22 + 5 ) = 28 km / hr distance travelled downstream = 112 km time taken = distance / speed = 112 / 28 = 4 hours answer : option b"
Answer: B