Question

Three numbers are in the ratio $3:4:5$ and their L.C.M. is $2400.$What is their H.C.F?

• A. $200$
• B. $40$
• C. $80$
• D. $120$

Answer 1

The correct option is B $40$

Let the number be 3x,4x and 5x

Then their L.C.M=60x

$\therefore 60x=2400$

$\Rightarrow x=\frac{2400}{60}=40$

$\therefore$Numbers are $(3\times 40),(4\times 40)and(5\times 40)$

Then H.C.F=40