Correct Answer - Option 4 : 14

**Given: **

The upstream speed of a boat is 15 kmph and it travels a distance of 110 kms in 2 hours during downstream.

**Formula: **

Time taken by boat to travel upstream = D/(speed of bota in still water – speed of the stream)

Time taken by boat to travel downstream = D/(speed of bota in still water + speed of the stream)

**Calculation: **

The upstream speed of a boat is 15 kmph

Downstream speed = 110/2 = 55 kmph

Required time = 165/15 + 165/55 = 11 + 3 = 14 hours