Correct Answer - Option 1 : 40

**Given:**

A boat makes a round trip of 240 km in 13 hours when the speed of the stream is 14 km/hour

**Formula:**

Upstream = (u − v) km/hr

where “u” is the speed of the boat in still water

“v” is the speed of the stream

Downstream = (u + v) Km/hr

where “u” is the speed of the boat in still water

“v” is the speed of the stream

Speed of Boat in Still Water = (1/2)(Downstream Speed + Upstream Speed)

Speed of Stream = (1/2)(Downstream Speed – Upstream Speed)

**Calculation:**

Let the speed of the boat in still water be x km/hr

Upstream Speed = x - 14

Downstream Speed = x + 14

{120/(x - 14)} + {120/(x + 14)} = 13

⇒ x = 26

Downstream speed = x + 14 = 40 km/h

**∴ The downstream speed is 40 km/h.**