Question

Three numbers are in the ratio of $3:4:5$ and their $\text{L.C.M.}$ is $2400.$ Their $\text{H.C.F.}$ is

• A. $20$
• B. $80$
• C. $40$
• D. $60$

Answer 1

The correct option is C $40$

Let the numbers be $3x,4x$ and $5x.$
Then, clearly, $\text{H.C.F.}=x$
and $\text{L.C.M.}=60x$
$\Rightarrow 60x=2400$
$\Rightarrow x=40$