Question

Q46. A steamer goes downstream from one port to another in 4 hours. It covers the same distance upstream in 5 hours. If the speed of stream is 2 km/h, the distance between the two ports is:

• A. (a) 50 km
• B. (b) 60 km
• C. (c) 70 km
• D. (d) 80 km

Answer 1

The correct option is D

(d) 80 km

Let the distance = x km

Speed of steamer in still water = y km/h -->

$\frac{x}{y+2}=4and\frac{x}{y-2}=5$

X = 4(y + 2) and x = 5(y -2)

4 (y +2) = 5 (y -2)

4y + 8 = 5y – 10

4y = 18 km/h

X = 4 (y +2) = 4(18 +2) = 80km