Find the HCF and LCM of 42,90 and 72
Answers
Step-by-step explanation:
Calculate Greatest Common Factor for :
42, 90 and 72
Factorize of the above numbers :
42 = 2 • 3 • 7
90 = 2 • 32 • 5
72 = 23 • 32
Build a prime factors table
Number of times each prime factor
appears in the factorization of :
Prime
Factor Number
42 Number
90 Number
72 G.C.F
(min)
2 1 1 3 1
3 1 2 2 1
5 0 1 0 0
7 1 0 0 0
GCF = 2 • 3
Greatest Common Factor is :
6
Answer:
LCM (42, 90, 72) = 2520
HCF (42, 90, 72) = 6
Step-by-step explanation:
Prime Factorisation of 42
42 = 2 × 3 × 7
Prime Factorisation of 90
90 = 2 × 3 × 3 × 5 = 2 × 3² × 5
Prime Factorisation of 72
72 = 2 × 2 × 2 × 3 × 3 = 2³ × 3²
LCM (42, 90, 72)
= Product of highest power of the prime factors
= 2³ × 3² × 5 × 7
= 2520
HCF (42, 90, 72)
= Product of lowest power of the prime factors present in all numbers
= 2 × 3
= 6