CBSE Class 10 Mathematics Basic 2024: question 21

Hints

Open one hint at a time and try again before the next.

Step-by-step solution

Each step shows the marks it earns, as an examiner would award them. Checked by an independent re-solve from the question paper.

1. Write 84 as a product of primes: $84=2\times 2\times 3\times 7=2^2\times 3\times 7$

   ½ mark

2. Write 144 as a product of primes: $144=2\times 2\times 2\times 2\times 3\times 3=2^4\times 3^2$

   ½ mark

3. HCF is the product of the smallest powers of the common prime factors: $\text{HCF}=2^2\times 3=12$

   1 mark

Answer: HCF(84, 144) = 12

Revise the chapter

• Chapter: Real Numbers (notes, formulas, where marks are lost and every past question)
• Topic: HCF and LCM by Prime Factorisation