Question | A man swims 12 km downstream and 10 km upstream. If he takes 2 hours each time, what is the speed of the stream? | |
Type | multiple_choice | |
Option | 1 km/hr | incorrect |
Option | 0.5 km/hr | correct |
Option | 1.5 km/hr | incorrect |
Option | 0.7 km/hr | incorrect |
Speed downstream = Distance/time = 12/2 = 6 km/hr
Speed downstream = Distance/time = 10/2 = 5 km/hr
Apply formula: Speed of stream = 1/2 (speed downstream – speed upstream)
X = 6 km/hr
Y= 5 km/hr
∴ Required speed = 1/2 (6 -5) km/hr = ∗ 1= 0.5 km/hr