Question

Find LCM:
$20,40$ and $50$.

Answer 1

Given numbers are $20,40$ and $50$.

The numbers can be represented as the product of their prime factors, as:

$20=1\times 2\times 2\times 5$

$40=1\times 2\times 2\times 2\times 5$

$50=1\times 2\times 5\times 5$

We know that, $LCM$ is the product of the highest powers of all prime factors.

Here, $2$ and $5$ are the prime factors. The highest power of $2$ is $3$ and that of $5$ is $2$.

Hence, $LCM=2^3\times 5^2$

$=2\times 2\times 2\times 5\times 5$

$=200$

Hence, the $LCM$ of $20,40$ and $50$ is $200$.