Question

(a) Write 140 as a product of prime factors. (b) Find the lowest common multiple (LCM) of 84 and 140.

Answer 1

`\begin{gathered} \text{Prime Factor of }140 \\ \\ 140=2*2*5*7 \end{gathered}`

By listing the multiples of 84 and 140, we have

Multiples of 84 → 84, 168, 252, 336, 420, 504

Multiples of 140 → 140, 280, 420, 560

Therefore, the LCM of 84 and 140 is 420.