Question

Find the LCM of

a) 9, 12,15 b) 112 , 168 c) 32, 36,40

Answer 1

$$\begin{gathered} \mathrm{a})3\left|9,12,15\right| \\ \overline{\left|3,4,5\right|} \\ \mathrm{So}\mathrm{L}.\mathrm{C}.\mathrm{M}\mathrm{of}9,12\mathrm{and}15=3\times 3\times 4\times 5=180 \\ \mathrm{b})2\left|112,68\right| \\ \overline{2\left|56,34\right|} \\ \overline{\left|28,17\right|} \\ \mathrm{So};\mathrm{L}.\mathrm{C}.\mathrm{M}\mathrm{of}112\mathrm{and}68=2\times 2\times 28\times 17=1904 \\ \mathrm{c})2\left|32,36,40\right| \\ \overline{2\left|16,18,20\right|} \\ \overline{2\left|8,9,10\right|} \\ \overline{\left|4,9,5\right|} \\ \mathrm{So};\mathrm{L}.\mathrm{C}.\mathrm{M}\mathrm{of}32,36\mathrm{and}40=2\times 2\times 2\times 4\times 9\times 5=1440 \end{gathered}$$