The ratio between the speeds of two cars is 4 : 5. If the first car covers a distance of 320 km in 4 hours, what is the speed of the second car? MCQ with Answer and Explanation
The ratio between the speeds of two cars is 4 : 5. If the first car covers a distance of 320 km in 4 hours, what is the speed of the second car?
A. 100 km/h
B. 110 km/h
C. 90 km/h
D. 80 km/h
Answer: Option A
Solution (By JKSSB Mock Tests)
Speed of first car = 320 / 4 = 80 km/h. Ratio of speeds is 4:5, so 4 parts = 80 km/h => 1 part = 20 km/h. Speed of second car = 5 parts = 5 * 20 = 100 km/h.
A person walks from his home to his office at 4.5 km/h and reaches 12 minutes late. If he walks at 6 km/h, he reaches 3 minutes early. Find the distance.
Explanation:
New speed = 5/7 of usual speed => New time = 7/5 of usual time. Difference = 2/5 of usual time = 12 minutes. 1/5 of usual time = 6 minutes => Usual time = 6 * 5 = 30 minutes.
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