This is the basic and exam oriented question from real numbers in which we have given two numbers 23 and 31 and we have to find the HCF and LCM of the given numbers by using the method of prime factorization.
RS Aggarwal, Class 10, chapter 1B, question no 1(ii)
23 and 31 are prime numbers.
LCM ( 23 and 31 ) =23×31=713
HCF ( 23 and 31 ) =1
verification
HCF×LCM=1×713=713
product of given numbers = 23×31=713
⇒HCF×LCM = product of given numbers.
verified.