BSF Staff Nurse - 2015
Non Nursing Subjects
Easy

The LCM and HCF of two numbers are 150 and 5 respectively. If one number is 25, then other number is?

Appeared in: BSF Staff Nurse - 2015

Explanation

  • The fundamental principle in this problem is that the product of two numbers is equal to the product of their Least Common Multiple (LCM) and Highest Common Factor (HCF).
  • The formula is: Number 1 × Number 2 = LCM × HCF.
  • Given values are: LCM = 150, HCF = 5, and one number = 25.
  • Substituting the values: 25 × Number 2 = 150 × 5.
  • The product of the LCM and HCF is 150 × 5 = 750.
  • To find the other number, we divide this product by the known number: 750 ÷ 25 = 30.

Why Other Options Were Wrong

  • Option B: This is an incorrect calculation. If the other number were 24, the product of the two numbers would be 25 × 24 = 600, which does not equal the product of the LCM and HCF (750).
  • Option C: This is an incorrect calculation. If the other number were 28, the product of the two numbers would be 25 × 28 = 700, which is not equal to the product of the LCM and HCF (750).
  • Option D: This is an incorrect calculation. If the other number were 20, the product of the two numbers would be 25 × 20 = 500, which does not equal the product of the LCM and HCF (750).

Related Visual

Visual explanation — Related Visual
Clinical Relevance
  • Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Relationship between LCM, HCF, and the product of two numbers as background academic context rather than a clinical decision trigger.
  • This question tests basic mathematical aptitude, which is a component of the general intelligence section in many nursing and other competitive examinations.
  • Strong numerical skills are essential for nurses for tasks like medication dosage calculation, IV drip rate monitoring, and interpreting patient data charts.
  • What if the LCM was 300 and the HCF was 10? Keeping one number at 25, the other number would be (300 × 10) / 25 = 3000 / 25 = 120. The formula remains the same regardless of the values.
How to Approach the Question
  • First, identify the type of question. This is a direct application of a standard mathematical formula involving LCM and HCF.
  • Recall the key formula: Product of two numbers = Product of their LCM and HCF.
  • List all the values provided in the question: LCM = 150, HCF = 5, and one of the numbers = 25.
  • Substitute these values into the formula: 25 × (Second Number) = 150 × 5.
  • Solve the equation for the unknown 'Second Number'.
  • Perform the calculation: (150 × 5) / 25 = 750 / 25 = 30.
Concept Tested & Keywords
  • Concept Tested: Relationship between LCM, HCF, and the product of two numbers
  • Stem keywords: LCM, HCF, two numbers
  • Lead-in keywords: then other number is?

Question ID

QBkvCedkF3Ky835lqxyjSZ

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