Example: 5 and 7 List the multiples of 5. 5, 10, 15, 20, 25, 30, 35, 40... List the multiples of 7. 7, 14, 21, 28, 35, 42... The LCM is the first number that appears on both lists.
The first common multiple of 3 4 5 and 7 is 420.
To find the common multiples of 2, 3, and 7, we first list the multiples of each number: Multiples of 2: 2, 4, 6, 8, 10, 12, ... Multiples of 3: 3, 6, 9, 12, 15, 18, ... Multiples of 7: 7, 14, 21, 28, 35, ... The first common multiple of 2, 3, and 7 is 6, as it is the smallest number that is a multiple of all three numbers. The second common multiple is 12, as it is the next number that is a multiple of all three numbers.
These are the first 90 multiples of 7:714212835424956637077849198105112119126133140147154161168175182189196203210217224231238245152159266273280287294301308315322329336343350357364371378385392399406413420427434441448455462469476483490497504511518525532539546553560567574581588595602609616623630
245 is not prime. Composite: (5 x 49 or 5 x 7 x 7) Also you can automatically determine a number as composite if: it ends with 2, 4, 6, 8, and 0: multiples of 2; or it ends with 5: multiples of 5.
There is an infinite number of common multiples for these numbers!
7,14,21,28,35
Example: 5 and 7 List the multiples of 5. 5, 10, 15, 20, 25, 30, 35, 40... List the multiples of 7. 7, 14, 21, 28, 35, 42... The LCM is the first number that appears on both lists.
This is done by multiplying 7 by the first 5 natural numbers.So we have 7x1=77x2=147x3=217x4=287x5=35
3521674
The first four multiples of five: 5, 10, 15, 20
There are infinitely many common multiples of 3, 5 and 7, each one 105 larger than the previous one. Or to put it another way: the common multiples of 3, 5 and 7 are the multiples of their lowest common multiple which is 105. ie their common multiples are all the multiples of 105, of which there is no end - there is an infinite number of multiples of 105 (or any other number [except zero]).
35 and all of its integral multiples
7, 14, 21, 28, 35
7, 14, 21, 28, 35
only two whole number multiples equal 35... they are 7 and 5 but you can have 4.375 4 and 2 as multiples.
35 and 70