SOLUTION: How many common multiples of 14 and 21 are there between 200 and 400?

Algebra.Com
Question 1049660: How many common multiples of 14 and 21 are there between 200 and 400?
Found 3 solutions by ikleyn, MathTherapy, Alan3354:
Answer by ikleyn(52787)   (Show Source): You can put this solution on YOUR website!
.
How many common multiples of 14 and 21 are there between 200 and 400?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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.


Answer by MathTherapy(10552)   (Show Source): You can put this solution on YOUR website!

How many common multiples of 14 and 21 are there between 200 and 400?
LCM of 14 and 21 is 42
There are 5 multiples of 42, between 200 and 400. They are:
Answer by Alan3354(69443)   (Show Source): You can put this solution on YOUR website!
The LCM is 42.
--> 42 times 5, 6, 7, 8 & 9.

RELATED QUESTIONS

2. How many multiples of 11 are there between 200 and 500? a. 25 b. 26 c. 27 d. 28 (answered by Theo)
how many numbers are there between 200 and 500 which are multiples of 3 and whose cube... (answered by Alan3354)
how many multiples of 7 are there between 250 and... (answered by Fombitz)
how many multiples of 4 are there between 17 and... (answered by Boreal)
How many common multiples of 3,5 and 7 are there between 1 and 5000? How we have to... (answered by KMST,MathTherapy)
How many integers between 1 and 200 are multiples of both 3 and 5 but not of either 4 or... (answered by JBarnum)
How many integers between 1 and 10 are multiples of either 3 or 5 but not multiples of... (answered by solver91311,MathTherapy)
how many numbers between 200 and 400 are divisible by 3,4 and 5... (answered by ikleyn)
how many numbers between 200 and 400 are divisible by 3,4 and 5... (answered by ikleyn)