Question

7. Ratio of LCM to the HCF of 5, 15 and 20 is
a) 1:12
b) 12:1
c) 1:1
d) None of the above​

Answer 1

Answer:

b) 12 : 1

Step-by-step explanation:

Given,

• 5, 15 and 20.

To Find,

• The Ratio of LCM and HCF.

Solution,

Finding LCM,

5 | 5, 15, 20

3 | 1 , 3 , 4

4 | 1 , 1 , 4

| 1 , 1 , 1

LCM of 5, 15 and 20 = 5 × 3 × 4 × 1

LCM of 5, 15 and 20 = 60

Finding HCF,

Factors of 5 = 1 and 5

Factors of 15 = 1, 3, 5 and 15

Factors of 20 = 1, 2, 4, 5, 10 and 20

Common Factors = 1 and 5

HCF of 5, 15, and 20 = 1 × 5

HCF of 5, 15 and 20 = 5

The Ratio of 5, 15 and 20 = 60 : 5

The Ratio of 5, 15 and 20 = 12 : 1

Required Answer,

• The Ratio of 5, 15 and 20 is 12 : 1.