Question

The HCF of two numbers is 27 and their LCM is 162. If one of the numbers is 54, what is the other number?

(a) 36
(b) 45
(c) 9
(d) 81

Answer 1

(d) 81
Let the two numbers be x and y.
It is given that:
x = 54
​HCF = 27
LCM = 162
We know,
x $\times$ y = HCF $\times$ LCM
$\Rightarrow$54 $\times$ y = 27 $\times$ 162
$\Rightarrow$ 54y = 4374
$\Rightarrow$ ∴​ y = $\frac{4374}{54}$ = 81