The L.C.M. of two numbers is 2376 and their H.C.F. is 33. If one number is 297, find the other number.

Difficulty: Easy

Correct Answer: 264

Explanation:


Introduction / Context:
The fundamental identity for two positive integers a and b is a*b = gcd(a, b) * lcm(a, b). Knowing the LCM, HCF, and one number allows us to compute the other directly by rearrangement.


Given Data / Assumptions:

  • LCM = 2376.
  • HCF = 33.
  • One number a = 297.
  • Find the other number b.


Concept / Approach:
Use b = (HCF * LCM) / a. Ensure a divides the product exactly, since the result must be an integer. Perform simplification before multiplication if convenient.


Step-by-Step Solution:

Compute b = (33 * 2376) / 297.Observe 2376 / 297 = 8 (since 297 * 8 = 2376).Therefore b = 33 * 8 = 264.


Verification / Alternative check:
Check gcd(297, 264) = 33 and lcm(297, 264) = (297*264)/33 = 2376. Both match the given data, confirming correctness.


Why Other Options Are Wrong:

  • 216, 642, 792, 198: These do not satisfy both the specified HCF and LCM simultaneously with 297 under the product identity.


Common Pitfalls:

  • Miscalculating the quotient 2376/297.
  • Forgetting to divide by the known number after multiplying HCF and LCM.


Final Answer:
264

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