Question

Write the difference between the $LCM$ of $80,64$ and the $LCM$ of $90,72$.

Answer 1

$80=2\times 2\times 2\times 2\times 5$

$64=2\times 2\times 2\times 2\times 2\times 2$

L.CM of $80,64=2\times 2\times 2\times 2\times 2\times 2\times 5$

$=320$

$\begin{array}{cc}90& =2\times 3\times 3\times 5\\ 72& =2\times 2\times 2\times 3\times 3\\ LCMOF72,90& =2\times 2\times 2\times 3\times 3\times 5\\ & =360\end{array}$

difference $=360-320=40$