जॉइन Examsbookउत्तर : 3. "3 hrs 30 min"
Amith can row a boat d km upstream and the same distance downstream in 5 hours 15 minutes. Also, he can row the boat 2d km upstream in 7 hours. How long will it take to row the same distance 2d km downstream for Amith ?5
प्र: Amith can row a boat d km upstream and the same distance downstream in 5 hours 15 minutes. Also, he can row the boat 2d km upstream in 7 hours. How long will it take to row the same distance 2d km downstream for Amith ?
- 14 hrs 10 minfalse
- 23 hrs 15 minfalse
- 33 hrs 30 mintrue
- 44 hrs 1 minfalse
- उत्तर देखें
- Workspace
उत्तर : 3. "3 hrs 30 min"
व्याख्या :
Answer: C) 3 hrs 30 min Explanation: Let the speed of boat and stream be x and y kmph respectively. According to question d/x+y + d/x-y = 5h 15m or 21/4 hrs ......(i) and 2d/x-y = 7...... (ii) From eq. (i) and (ii) 2d/x+y = 7/2 Hence, Amith will take to row 2d km distance downstream in 7/2 hrs = 3.5 hrs = 3 hrs 30 min.