Question

Two people are paddling a canoe downstream with a speed of 5 km/h relative

to the river. If the river is flowing at 15 km/h, how long will it take them to
reach the canoe dock 30 km away?
A. 0.5 h
B. 1.0 h
C. 3.0 h
D. 1.5 h
SUBMIT

Answer 1

D. 1.5 h

Step-by-step explanation:

Canoe speed relative to river = 5 km/h

River speed relative to stationary observer on the bank = 15 km/h

Canoe speed (downstream) relative to observer = 5 km/h + 15 km/h =

20 km/h.

Speed = distance/time

time = distance / speed

Time to reach the canoe dock = 30 km / 20 km/h = 1.5 hours

Answer: 1.5 h