A fisherman can row upstream at 2 mph and downstream at 8 mph. He started rowing upstream until he got tired and then rowed downstream to his starting point. How far did the fisherman row if the entire trip took 7 hours?
Mathematics · High School · Thu Feb 04 2021
Answered on
Let the distance rowed by fisherman in upstream/downstream is d
Formula Used : Time = distance/speed
according to question fisherman rowed with speed of 2 mph and 8mph for d and d distance in total of 7 hours , so
d/2 + d/8 = 7
L.C.M of 2 and 8 is 8
(4d + d)/8 =7
Cross - multiplying, we get
5d = 56
dividing both sides by 5, we get
5d/5 = 56/5
d = 11.2 miles
2d = 2 *11.2 = 22.4 miles { because he rowed d in upstream and d in downstream }
So, total distance rowed by fisherman is 22.4 miles