Question

Deepti can row downstream 20km in 2hours and upstream 4km in 2hours. Find her speed of rowing in still water and the speed of the current.Please pleaseee.. answer fast.

Answer 1

let speed of stream be y km/h
and speed of boat be x km/h
so speed of boat in downstream bex+ykm/h
and speed of boat in upstream be x-y km/h
according to question,
20/x+y=2
=x+y=10......(1)
and
4/x-y=2
x-y=2.....(2)
(1)+(2)
=x+y+x-y=10+2
=2x=12
=x=6km/h......(3)
now putting value of (3)in (1)
6+y=10
y=4km/h

Answer 2

$hello$

$<b>$

let speed of stream be (y) km/h

and speed of boat be (x) km/h

so speed of boat in downstream be(x+y)km/h

and speed of boat in upstream be (x-y) km/h

according to question,

$\frac{20}{x + y} = 2$

» x+y=10____(1)

and

$\frac{4}{x - y} = 2$

» x-y=2_____(2)

(1)+(2)

» x+y+x-y=10+2

» 2x=12

» x=6km/h_____(3)

now putting value of (3)in (1)

» 6+y=10

» y=4km/h