What's the Lowest Common Multiple (LCM) of 7 and 8?

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Answer 1 · 2018-02-01T17:10:23

56

write down the multiple of 7, n then 8. choose the one that's common and the least. :)

multiples of 7 #=>7, 14, 21, 28, 35, 42, 49, color(red)(56), 63....#
multiples of 8 #=>8, 16, 24, 32, 40, 48, color(red)(56), 64, 72....#

so the lcm, I.e. least common multiple of 7 and 8 is, 56.

Answer 2 · 2018-02-06T20:06:32

#7xx8=56#
They have no common factors apart from #1#

#7 and 8# are consecutive numbers.

Therefore they have no common factors apart from #1#

The first time they will share a common multiple is with their own product.

#7 xx8= 56#

Looking at their prime factors:

#" "8 = " "2xx2xx2#
#" "7 = 7#

#LCM = 7 xx2xx2xx2 =56#