Let the normal bicycling 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 = 45/(x+2) hours
and
Time taken in going against the wind = 33/(x-2) hours
And Both times are same , according to the question
So
45/(x+2) = 33/(x-2)
On cross multiplying, we get
45(x-2) = 33(x+2)
45x-90 = 33x+66
Add 90 to both sides
45x -90 + 90 = 33x + 66 +90
45x = 33x +156
Subtract 33x from both sides
45x - 33x = 33x - 33x +156
12x = 156
Divide both sides by 12
x= 13
That implies
The normal bicycling speed = 13 Miles per hour