जॉइन Examsbookउत्तर : 2. "1 hr 20 min"
A person takes 20 minutes more to cover a certain distance by decreasing his speed by 20%. What is the time taken to cover the distance at his original speed ?5
प्र: A person takes 20 minutes more to cover a certain distance by decreasing his speed by 20%. What is the time taken to cover the distance at his original speed ?
- 11hrfalse
- 21 hr 20 mintrue
- 31 hr 10 minfalse
- 450 minfalse
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उत्तर : 2. "1 hr 20 min"
व्याख्या :
Answer: B) 1 hr 20 min Explanation: Let the distance and original speed be 'd' km and 'k' kmph respectively. d/0.8k - d/k = 20/60 => 5d/4k - d/k = 1/3 => (5d - 4d)/4k = 1/3 => d = 4/3 k Time taken to cover the distance at original speed = d/k = 4/3 hours = 1 hour 20 minutes.