| Question | A man rows downstream at 20 km/hr and rows upstream at 15 km/hr. At what speed he can row in still water? | |
| Type | multiple_choice | |
| Option | 17.5 km/hr | correct |
| Option | 18 km/hr | incorrect |
| Option | 20.5 km/hr | incorrect |
| Option | 22 km/hr | incorrect |
Apply formula: Speed in still water 1/2
(speed downstream + speed upstream)
Speed downstream = 20 km/hr
Speed upstream = 15 km/hr
∴ Required speed = 1/2 (20 + 15) km/hr
= 1/2 * 35 = 17.5 km/hr
