How many four-digit numbers N = abcd satisfy all of the following conditions?
1. 4000 <= N < 6000
2. N is a multiple of 5.
3. N is not a mutlple of 3
There are 400 numbers that are divisible by 5 within the range. Of these, 133 of them are divisible by 15, so your answer is 400-133 = 267.
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