This is Brute Force method but takes very less time because we just need to check number is not div by 2,3 or 5.
Total no of possible outcomes N(s) = 100
N(e)=Number's not divisible by (2 OR 3 OR 5) = (Not Div by 2 AND Not Div by 3 Not Div by 5 ) /// Demargon's law
N(e) = {1,7,11,13,17,19,23,29,31,37,41,43,47,49,53,59,61,67,71,73,77,79,83,89,91,97} = 26
Prob = N(e) / N(s) = 26/100 = 0.26
Answer is 0.26.