Here is the formula for Evasion anad the likeliness of hitting a Pokemon:
A = is the base accuracy of the move (in percent - e.g. a base accuracy of 95 is counted as 0.95)
Accuracy = The amount of boost/fall the accuracy of the move has at that moment (in percent - e.g. 3 boosts in accuracy make the value 2)
Evasion = The amount of evasion boosts the Pokemon has got (in percent - e.g. lowering evasion by two stages lowers this number to 0.6)
I took the move to be 100% accurate, and has no accuracy boosts.
So after doing the math, here's what I got:
#33.33% chance of hitting.
Hope I helped!