The HCF of two numbers is 6 and their LCM is 432. If one of the numbers is 48,…
2019
The HCF of two numbers is 6 and their LCM is 432. If one of the numbers is 48, the other number is:
- A.
52
- B.
42
- C.
27
- D.
54
Attempted by 2 students.
Show answer & explanation
Correct answer: D
Concept
For two positive integers a and b, the product of the numbers equals the product of their HCF and LCM: a × b = HCF(a, b) × LCM(a, b). Therefore, when one number and both measures are known, the other number is obtained by dividing HCF × LCM by the known number.
Application
Let the other number be x.
Apply the identity: 48 × x = 6 × 432.
Calculate the product on the right: 6 × 432 = 2592, so 48 × x = 2592.
Divide both sides by 48: x = 2592 ÷ 48 = 54.
Cross-check
The pair 48 and 54 has HCF 6. Also, (48 × 54) ÷ 6 = 432, so its LCM is 432; both given conditions are satisfied.
Thus, the other number is 54.
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