A motorboat tracks 36 km downstream in 3 hours and spans the same stretch upstream in 4.5 hours. Find the speed of the current. MCQ with Answer and Explanation

A motorboat tracks 36 km downstream in 3 hours and spans the same stretch upstream in 4.5 hours. Find the speed of the current.
A. 2.0 km/h
B. 1.5 km/h
C. 2.5 km/h
D. 3.0 km/h
Answer: Option A
Solution (By JKSSB Mock Tests)
Downstream speed = 36 / 3 = 12 km/h. Upstream speed = 36 / 4.5 = 8 km/h. Speed of current = (12 - 8) / 2 = 4 / 2 = 2 km/h.

Discuss this Question (0)

No comments yet. Be the first to start the discussion!

Practice More Time Speed and Distance Questions

Question #1
A courier covers 40 km of his shift route at 20 km/h and the remaining 60 km at 30 km/h. Find his average speed across the whole shift.
A. 25 km/h
B. 28 km/h
C. 24 km/h
D. 26 km/h

Correct Answer: Option A


Explanation:
Total distance = 40 + 60 = 100 km. Time for first sector = 40 / 20 = 2 hours. Time for second sector = 60 / 30 = 2 hours. Total time = 4 hours. Average speed = 100 / 4 = 25 km/h.

This question belongs to: Maths Time Speed and Distance
Question #2
A student walks from his quarter block to the academy center at 4 km/h and arrives 8 minutes late. If he manages a pace of 5 km/h, he arrives 4 minutes early. Find the track distance.
A. 4.0 km
B. 5.0 km
C. 4.5 km
D. 3.5 km

Correct Answer: Option A


Explanation:
Time difference = 8 - (-4) = 12 minutes = 10/60 = 1/5 hours. Let distance be d. d/4 - d/5 = 1/5 => d/20 = 1/5 => d = 4 km.

This question belongs to: Maths Time Speed and Distance
Question #3
A locomotive running at 54 km/h takes 20 seconds to completely cross a platform. If it takes 8 seconds to pass a standing point observer, find the platform length.
A. 180 meters
B. 200 meters
C. 160 meters
D. 220 meters

Correct Answer: Option A


Explanation:
Speed of train = 54 * (5/18) = 15 m/s. Length of train = Speed * Time to cross observer = 15 * 8 = 120 meters. Total distance to cross platform = Speed * Time = 15 * 20 = 300 meters. Platform length = 300 - 120 = 180 meters.

This question belongs to: Maths Time Speed and Distance