The HCF of two numbers is 12, and their product is 4320. How many such pairs…
2019
The HCF of two numbers is 12, and their product is 4320. How many such pairs of numbers are possible?
Answer: B. 4 — Let the numbers be 12a and 12b, where HCF(a, b) = 1. Then 12a × 12b = 4320 ⇒ a × b = 4320 ÷ 144 = 30. Coprime pairs with product 30 are (1,30), (2,15),…
- A.
2
- B.
4
- C.
1
- D.
3
Attempted by 190 students.
Show answer & explanation
Correct answer: B
Let the numbers be 12a and 12b, where HCF(a, b) = 1. Then 12a × 12b = 4320 ⇒ a × b = 4320 ÷ 144 = 30. Coprime pairs with product 30 are (1,30), (2,15), (3,10), (5,6). Hence, 4 pairs are possible.
Loading lesson…