Practicing Success
The speed of a boat going downstream is 22 km/h. The speed of the stream is 1 km/h. How much distance in total will the boat cover going 3 hours downstream and 2 hours upstream? |
112 km 94 km 106 km 102 km |
106 km |
we know that, upstream speed = a - b downstream speed = a + b Where a is speed of boat and b is speed of stream Given that, a + b = 22km/hr and speed of stream b = 1 km/hr So, a = 22 - 1 = 21 km/hr Distance = Speed × Time Total distance = 3 (a + b) + 2 (a - b) = 5a + by using the above value of a and b Total distance = 5 × 21 + 1 = 106 km |