Question

What is the LCD of `1/6, 1/2` and `7/9`?

Answer 1

LCM = 2xx3 xx 3 = 18# #

Explanation:

This can be done using the product of prime factors for each value.
To have 6 as a factor, means there has to be 2 and a 3.
To have 9 as a factor, means there has to be 3 and another 3.

But as we want the LOWEST common multiple, we do not want unnecessary duplicates.

`color(white)(xxxxxx) 6 = 2xx3`
`color(white)(xxxxxx) 2 = 2`
`color(white)(xxxxxx) 9 = color(white)(xxx)3xx3`

`color(white)(xxx) LCM = 2xx3 xx 3 = 18`

Of course, the best method is a solid knowledge of the times tables.