GeminiHeat wrote:
How many positive integers less than 100 are neither multiples of 2 or 3.
a) 30
b) 31
c) 32
d) 33
e) 34
Multiples of 2: 2, 4, 6, ..., 96, 98
98/2 = 49, so there are
49 multiples of 2
Multiples of 3: 3, 6, 9, ..., 99
99/3 = 33, so there are
33 multiples of 3
At this point we have counted some multiples TWICE. For example, we counted 6 TWICE, we counted 12 TWICE and so on.
In fact, we counted all multiples of 6 TWICE
Multiples of 6: 6, 12, 18..., 96
96/6 = 16, so there are 16 multiples of 6So.....TOTAL multiples of 2 OR 3 =
49 +
33 -
16 =
66There are 99 positive integers that are less than 100
So, the TOTAL number of those integers that are NEITHER multiples of 2 or 3 = 99 -
66 = 33
Answer: D
Cheers,
Brent