Question

A man can row 7 (1/2) km/h in still water. If in a river running at 1.5 km an hour it takes him 50 minutes to row to a place and back, how far off is the place?

Answer 1

Answer:

distance is 3 km

Step-by-step explanation:

Speed Downstream = (7.5 + 1.5) kmph = 9 kmph

Speed Upstream = (7.5 - 1.5) kmph = 6 kmph

Let the required distance be x km. Then,

x/9 + x/6 = 50/60

2x + 3x = 5/6 × 18 = 5x = 15, x = 3

Hence the required distance is 3 km.

if you like my ans please support by giving thanks

Answer 2

Answer:

Speed of downstream =(7.5+1.5)= 9km/hr

Speed of upstream= 7.5-1.5=6 km/hr

Let the distance be X km

Then X/9+X/6=50/60

2x+3x/18=5/6 i.e 2x+3x=5/6×18

5x=15 therefore X=3km

Distance is 3km