Question

If the HCF and LCM of two numbers are $13$ and $1989$ respectively and one of the number is $221$, determine the other number.

Answer 1

Let Suppose we have two numbers $a$ and $b$, then we have a rule i.e $a\times b=HCF(a,b)\times LCM(a,b)$, which means that product of those two numbers is equal to the product of their LCM and HCF

Given : $HCF=13andLCM=1989$, $a=221$

so using the property, we have $221\times b=13\times 1989$

$b=\frac{13\times 1989}{221}$

$b=13\times 9$

$b=117$

Hence the other number is $117$