A motorboat rows 16 km/h in still water and the speed of the river current is 4 km/h. Find the time taken to row 80 km downstream. MCQ with Answer and Explanation
Question
Report Error
Discuss this Question (0)
Practice More Time Speed and Distance Questions
Question #1
Report Error
A passenger coach locomotive 120 meters long passes a clear roadside post marker in 6 seconds flat. Find the time needed to cross an extensions platform 240 meters long.
Correct Answer: Option A
Explanation:
Speed of coach locomotive = 120 / 6 = 20 m/s. Total distance to clear platform stretch = 120 + 240 = 360 meters. Time required = 360 / 20 = 18 seconds.
Speed of coach locomotive = 120 / 6 = 20 m/s. Total distance to clear platform stretch = 120 + 240 = 360 meters. Time required = 360 / 20 = 18 seconds.
This question belongs to:
Maths
Time Speed and Distance
Question #2
Report Error
Two cars leave a location simultaneously at a right angle to each other. Their speeds are 36 km/h and 48 km/h respectively. Find the direct distance between them after 15 minutes.
Correct Answer: Option B
Explanation:
Time = 15 minutes = 0.25 hours. Distance covered by first car = 36 * 0.25 = 9 km. Distance covered by second car = 48 * 0.25 = 12 km. Since they travel at right angles, distance between them = sqrt(9^2 + 12^2) = sqrt(81 + 144) = sqrt(225) = 15 km.
Time = 15 minutes = 0.25 hours. Distance covered by first car = 36 * 0.25 = 9 km. Distance covered by second car = 48 * 0.25 = 12 km. Since they travel at right angles, distance between them = sqrt(9^2 + 12^2) = sqrt(81 + 144) = sqrt(225) = 15 km.
This question belongs to:
Maths
Time Speed and Distance
Question #3
Report Error
A traveler covers 1/3 of a distance at 20 km/h and the remaining 2/3 at 50 km/h. What is his net average speed for the entire distance?
Correct Answer: Option D
Explanation:
Let the total distance be 150 km. First part = 50 km; Time = 50/20 = 2.5 hours. Remaining part = 100 km; Time = 100/50 = 2 hours. Total distance = 150 km, Total time = 4.5 hours. Average speed = 150 / 4.5 = 1500 / 45 = 34.28 km/h.
Let the total distance be 150 km. First part = 50 km; Time = 50/20 = 2.5 hours. Remaining part = 100 km; Time = 100/50 = 2 hours. Total distance = 150 km, Total time = 4.5 hours. Average speed = 150 / 4.5 = 1500 / 45 = 34.28 km/h.
This question belongs to:
Maths
Time Speed and Distance
No comments yet. Be the first to start the discussion!