A motor vehicle completes a journey in 5 hours. It handles the first half of the stretch at 50 km/h and the second half at 30 km/h. Find the total distance wrapped. MCQ with Answer and Explanation
A motor vehicle completes a journey in 5 hours. It handles the first half of the stretch at 50 km/h and the second half at 30 km/h. Find the total distance wrapped.
A. 200 km
B. 175 km
C. 187.5 km
D. 192 km
Answer: Option C
Solution (By JKSSB Mock Tests)
Let the half distance be d. d / 50 + d / 30 = 5 => 8d / 150 = 5 => 8d = 750 => d = 93.75 km. Total distance = 2d = 187.5 km.
Explanation:
New speed = 4/5 of usual speed => New time = 5/4 of usual time. Difference = 1/4 of usual time = 10 minutes. Usual time = 10 * 4 = 40 minutes.
A thief is spotted by a policeman from a distance of 250 meters. When the policeman starts the chase, the thief also starts running. Assuming the speed of the thief to be 10 km/h and that of the policeman to be 12 km/h, how far will the thief have run before he is overtaken?
Explanation:
Relative speed = 12 - 10 = 2 km/h. Time taken to catch the thief = 0.25 km / 2 km/h = 1/8 hour. Distance run by the thief = Speed * Time = 10 km/h * (1/8) hour = 1.25 km = 1250 meters.
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