By applying the formula
LCM × HCF= 1st number × 2nd number

for eg one no. is given i.e. 2 and we have to find the other no HCF is given as 2 and LCM is 4
We know
HCF × LCM= 1st number × 2nd number
2 × 4= 2× 2nd number
2nd number will come out to be 4
We know the formula.
HCF*LCM of 2 numbers=1st number * 2nd number.
So by transferring 1st number to the L.H.S we get:
 \frac{HCF*LCM}{1st          _.number} =2nd_.number.
1 5 1