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. MCQ with Answer and Explanation
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.
A. 20 km
B. 12 km
C. 15 km
D. 18 km
Answer: Option C
Solution (By JKSSB Mock Tests)
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.
Explanation:
When A covers 100m, B covers 90m and C covers 81m. This means in a distance where B covers 90 meters, C covers 81 meters. Therefore, B beats C by 90 - 81 = 9 meters.
A boatman can row 16 km/h in still water. If the river velocity index tracks at 4 km/h, find the time interval required by the boat hull to row 48 km upstream.
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