Let the normal rowing speed with no wind = x mph
So , speed with the wind = (x+2) mph
and speed against the wind = (x-2) mph
It means
Time taken in going with the wind = Distance/speed = 42/(x+2) hours
and
Time taken in going against the wind = 34/(x-2) hours
And Both times are same , according to the question
So
42/(x+2) = 34/(x-2)
On cross multiplying, we get
42(x-2) = 34(x+2)
42x-84 = 34x+68
Add 90 to both sides
42x -84 + 84 = 34x + 68 +84
42x = 34x +152
Subtract 34x from both sides
42x - 34x = 34x - 34x +152
8x = 152
Divide both sides by 8
x= 19
That implies
The normal rowing speed = 19 Miles per hour
