Correct Answer - Option 3 : 80 km
Given:
The speed of a boat in upstream is 30 km/hr
The speed of the stream is 5 km/HR
Formula used:
Speed of boat in upstream = a - b
Speed of boat in downstream = a + b
where, a = Speed of boat, b = Speed of stream
Calculations:
According to the question, we have
Speed of boat is
⇒ a - 5 = 30
⇒ a = 35 km/hr
Now, The Speed of boat in downstream is
⇒ Speed of boat in downstream = 35 + 5
⇒ Speed of boat in downstream = 40 km/hr
The total Distance covered in downstream in 2 hours is
⇒ Distance covered = 40 × 2
⇒ Distance covered = 80 km
∴ Total distance covered in downstream in 2 hours is 80 km.
