Question

Find the first four common multiples of the following :

$3,4$ and $6$.

• A. $72,78,84,90$
• B. $12,24,36,48$
• C. $24,30,36,42$
• D. $8,12,16,21$

Answer 1

Answer: (B)

$12,24,36,48$

Multiples of $3=3,6,9,12,15,\mathrm{18..}$
Multiples of $4=4,8,12,16,\mathrm{20..}$

Multiples of $6=6,12,18,\mathrm{36..}$

The first common multiple will be $12$
And the next common multiples will be multiples of $12$
Hence, first four common multiples of $3,4,6$ are $12,24,36,48$