Answer:
22
Step-by-step explanation:
The least common multiple of 6 and 9 is 18. Consider a group of 18 numbers, 1–18, for example. The multiples of 6 are 6, 12, and 18, of which two are not multiples of 9.
There are 11 groups of 18 numbers in 1–200, with 2 left over. That means there will be 11×2 = 22 numbers that are multiples of 6 but not 9.
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200/18 = 11 remainder 2