Answer:
Let the speed of the boat in still water be x km/h and
that of the stream be Then,
Speed upstream
Speed downstream
Now, time taken to cover 32 km upstream
Time
taken to cover 36 km downstream
The
total time of journey is 7 h.
?(i)(1/2)
Time taken to cover 40 km upstream
Time
taken to cover 48 km downstream
In this
case, total time of journey is 9 h.
?(ii)
Putting
and
in Eqs.
(i) and (ii), we get
?(iii)
and
?(iv)(1/2)
By cross-multiplication, in Eqs
(iii) and (iv) we have
(1/2)
and
(1/2)
We have,
?(v)
and
?(vi)(1)
On adding Eqs. (v) and (vi), we
get
On putting the value of
in Eq.
(vi), we get
Hence, the speed of the boat =
10 km/h and the speed of the stream = 2 km/h (1/2)
You need to login to perform this action.
You will be redirected in
3 sec