Question

Let $\ast$ be a 'binary' operation on N given by $a\ast b=LCM(a,b)$ for all $a,b$ $ϵ$ $N$.

Find $5\ast 7$.

Answer 1

$a\ast b=$ $LCM$$(a,b)$ for all $a,b\in N$

$5\ast 7=LCM$$(5,7)$

$LCM$ of $5$ and $7=5\times 7=35$