The product of two numbers is 1521 and the HCF of these numbers is 13. Find the number of such pairs?

Question

Question

Answer 1

GIVEN:

The product of two numbers is 1521 and the HCF of these numbers is 13.

CONCEPT:
HCF: The highest common factor (HCF) is found by finding all common factors of two numbers and selecting the largest one.

CALCULATION:

Suppose the numbers are 13a and 13b as the HCF of these numbers is 13.

We can write:

13a × 13b = 1521

⇒ ab = 9

∴ Only possible pair is 13, 117

Mistake PointsAccording to question,

ab = 9

For a = 1 and b = 9

The numbers will be 13 and 117 and their HCF will be 13

Here we will not consider a = 3 and b = 3.

The numbers will be 39 and 39.

Here HCF would be 39 which does not satisfy the given condition.