Answer:
46
Step-by-step explanation:
he count of numbers from 1 to n that are divisible by k is integer part of (n/k).
So the numbers from 1 to 99 divisible by 3 is int(99/3) = 33
Those divisible by 5: int(99/5) = 19
From the sum of those two, subtract those divisible by 15 = int(99/15) = 6
That gives you 33+19-6 = 46.
Now subtract the 1 digit numbers: 3, 5, 6, 9, or four of them
46 - 4 = 42 is the answer.