A man can row2/3 rd of a kilo meter down stream in 5 minutes and return to the starting point in another
10 minutes. The speed of the man in still water is_ kmph.
ream, then the speed of the
Answers
Answer:
Let he speed of the man be x km/hr and that of the water current be y km/hr.
While going upstream, the relative speed of the man w.r.t stream is x−y km/hr.
While going downstream, the relative speed of the man w.r.t stream is x+y km/hr.
As per given condition,
x−y
3/4
=11
4
1
min and
x+y
3/4
=7
2
1
min
Dividing the above 2 equations,
x−y
x+y
=
2
3
→2(x+y)=3(x−y)
→5y=x
Putting this value of x in equation 2:
6x/5
3/4
=
120
15
x=5 km/hr
We can write three - quarters of a kilometer as 750 meters and 1114
1114
minutes as 675 seconds
Rateupstream=750675m/sec=109m/secRatedownstream=750450m/sec=53m/sec∴Rateinstillwater=12(109+53)m/sec=2518m/sec=(2518×185)km/hr=5km/hr
Rateupstream=750675m/sec=109m/secRatedownstream=750450m/sec=53m/sec∴Rateinstillwater=12(109+53)m/sec=2518m/sec=(2518×185)km/hr=5km/hr