A person walks from his home to his shop at a speed of 5 km/h and arrives 6 minutes early. If he walks at 4 km/h, he arrives 6 minutes late. Find the distance between his home and shop. MCQ with Answer and Explanation
A person walks from his home to his shop at a speed of 5 km/h and arrives 6 minutes early. If he walks at 4 km/h, he arrives 6 minutes late. Find the distance between his home and shop.
A. 5 km
B. 3 km
C. 4 km
D. 6 km
Answer: Option C
Solution (By JKSSB Mock Tests)
Time difference = 6 - (-6) = 12 minutes = 12/60 = 1/5 hour. Let distance be d. d/4 - d/5 = 1/5 => d/20 = 1/5 => d = 4 km.
Explanation:
Let speed of current be c. 24 / (9 + c) + 24 / (9 - c) = 6. Dividing by 6: 4 / (9 + c) + 4 / (9 - c) = 1 => 4(9 - c + 9 + c) = 81 - c^2 => 72 = 81 - c^2 => c^2 = 9 => c = 3 km/h.
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