Question

Find the LCM of the following. 28, 72, 98.​

Answer 1

Given numbers:-

$28, 72, 98$

We have to find the LCM

First, we need to find the prime factors,

Prime factor of $28$ are $2,2$ and $7.$

Prime factor of $72$ are $2,2,2,3$ and $3.$

Prime factor of $98$ are $2,7$ and $7.$

The least common multiple is the product of all factors in the greatest numbers of their occurrence,

LCM $=2\times 2\times 2\times 3\times 3\times 7\times 7$

LCM $=2^3\times 3^2\times 7^2$

LCM $=3528$

Hence, the LCM of $28, 72$ and $98$ is $3528.$

Answer 2

Given,

$28,72,98$

L.C.M (least common multiple): L.C.M is the smallest integer which is a multiple of two or more numbers.

To write the prime factors of $28,72,98$

$28=2\times2\times7\\72=2\times2\times2\times3\times3\\98=2\times7\times7$

Multiply the common prime factors from the above,

So,

$=2\times2\times7\times3\times3\times2\times7$

L.C.M of $28,72,98 = 3528$

Therefore, the L.C.M of $28,72,98$ is $3528$.