Q21 of 124 Page 1

HCF of two numbers is always a factor of their LCM (True/False).

True.

LCM of two or more numbers is always divisible by their HCF.

Example: Let us take two numbers 6 and 20.

The prime factorization of

6 = 2¹ × 3¹ and 20 = 2² × 5¹

HCF = 2

LCM = 2² × 3 × 5 = 60

∴ 2 is a factor of 60.

What is a composite number?

What is the HCF of the smallest composite number and the smallest prime number?

π is an irrational number (True/False).

The sum of two prime numbers is always a prime number (True/False).