Question 1049660
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How many common multiples of 14 and 21 are there between 200 and 400?
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Common multiples of 14 and 21 are those and only those integer numbers that are multiple of LCM(14,21) = 42.


There are not so many multiples of 42 between 200 and 400. 
They are 210, 252, 294, 336 and 378.
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