Prime Numbers, Hcf, Lcm

PRIMES NUMBERS , HCF , LCM.

The factors of a number are any numbers that divide into it exactly.

A prime number has exactly two factors, itself and 1.

The prime numbers are : 2,3, 5,7,11,13,17.19,23,29,31....

Prime factors are number which is a factor of another number and it is prime.

Write 120 , 210 as the product of theirs prime factors.

120= 2³ x3x5

210=2x3x5x7

Work out the HCF, highest common factor , and LCM, lowest common multiple, of 120 and 210:

HCF= 2x3x5=30 and LCM= 30 x 7 x 2² = 210 x 2 ² =120 x7=840