Question

Select the most appropriate option. Find the HCF of 30, 60 and 72. 
1. 2
2. 3
3. 6
4. 12

Answer 1

Correct Answer - Option 3 : 6

Given:

The numbers are 30, 60 and 72

Concept used:

HCF(highest common factor): this is the largest positive integer that divides each integer. This is sometimes called the greatest common divisor(G.C.D)

Calculation: 

Factor of 30 = 1 × 2 × 3 × 5

Factor of 60 = 1 × 2 × 2 × 3 × 5

⇒ 1 × 2² × 3 × 5

Factor of 72 = 1 × 2 × 2 × 2 × 3 × 3

⇒ 1 × 2³ × 3²

So from the above, we can say that the highest common integer = 2 × 3

⇒ 6

Then HCF of 30, 60 and 72 is 6

∴ The HCF of 30, 60 and 72 is 6