A boy goes to school at a speed of 3 km/h and returns to his village at a speed of 2 km/h. If he takes 5 hours in all, what is the distance between the school and the village? MCQ with Answer and Explanation
A boy goes to school at a speed of 3 km/h and returns to his village at a speed of 2 km/h. If he takes 5 hours in all, what is the distance between the school and the village?
A. 7 km
B. 8 km
C. 6 km
D. 5 km
Answer: Option C
Solution (By JKSSB Mock Tests)
Let distance be d. d/3 + d/2 = 5 => 5d/6 = 5 => d = 6 km.
Explanation:
When A covers 200m, B covers 180m and C covers 162m. This means in a match distance where B covers 180 meters, C covers 162 meters. Scaling down to 90 meters: B covers 90m, C covers 162 * (90/180) = 81m. Therefore, B beats C by 90 - 81 = 9 meters.
A baseline boat hull can row 12 km/h in still water. If the river current tracks a velocity of 4 km/h, find the exact sector distance covered downstream by the boat hull in 45 minutes flat.
A person covers a certain distance at a certain speed. If he reduces his speed by 20%, he takes 15 minutes more to cover the same distance. Find his usual time.
Explanation:
New Speed = 0.8 * Usual Speed. Since distance is constant, New Time = Usual Time / 0.8 = 1.25 * Usual Time. Increase in time = 0.25 * Usual Time = 15 minutes. Usual Time = 15 / 0.25 = 60 minutes.
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