Question

hello guys please give me answer it's urgent

Answer 1

Speed in Upstream =x -y .
( speed of boat = x , speed of stream =y )

Speed in downstream =x +y .

Time = Distance / Speed .
10=30/x-y + 44/x+y
Let 1/x-y = u and 1/x+y =v .

Then , 10= 30u + 44v .....eq (1 )

13 = 40/ x-y +55/x +y
13 = 40 u +55v. .......eq (2 )
Multiplying eq.1 by 4 and eq.2 by 3 ,we get :

40 = 120u + 176v
39 = 120u + 165v
Eleminating these two above equations :

v = 1/11
1/ x+y =1/11
x+y =11. ........eq (3)

putting value of v in equation 2 we get ,
u =1/5
1/x-y =1/5
x-y = 5. ........ eq (4)

Eleminating equation 3 &4 :
x = 8 ( speed of boat )
y = 3 ( speed of stream)

ThAnKs !✌️✌️