A motor car finishes a journey in 6 hours. It covers the first half of the distance at 40 km/h and the second half at 20 km/h. Find the total distance covered. MCQ with Answer and Explanation
A motor car finishes a journey in 6 hours. It covers the first half of the distance at 40 km/h and the second half at 20 km/h. Find the total distance covered.
A. 180 km
B. 200 km
C. 140 km
D. 160 km
Answer: Option D
Solution (By JKSSB Mock Tests)
Let the half distance be d. d / 40 + d / 20 = 6 => 3d / 40 = 6 => 3d = 240 => d = 80 km. Total distance = 2d = 160 km.
Two sprinters race on a 200-meter straight track. The ratio of their speeds is 4 : 5. When the winner crosses the finish line, how far away from the tape is the slower sprinter?
Explanation:
The faster sprinter covers 5 parts = 200 meters, so 1 part = 40 meters. In that same timeframe, the slower sprinter covers 4 parts = 4 * 40 = 160 meters. Distance remaining for the slower sprinter = 200 - 160 = 40 meters.
A train leaves a station at 4:00 PM and travels at an average speed of 60 km/h. Another train leaves the same station at 5:00 PM in the same direction at an average speed of 80 km/h. At what time will the second train catch up with the first train?
Explanation:
By 5:00 PM, the first train has traveled for 1 hour and covered 60 km. Relative speed = 80 - 60 = 20 km/h. Time needed to catch up = 60 / 20 = 3 hours. Catch up time = 5:00 PM + 3 hours = 8:00 PM.
Explanation:
Speed of B = 400 / 50 = 8 m/s. Distance covered by B when A crosses the finish line at 44 seconds = 8 * 44 = 352 meters. Winning margin = 400 - 352 = 48 meters.
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