MathsCBSE Class 10 · Standard · Sample paper, session 2024-25 · 2 marks · Very short answer

CBSE Class 10 Mathematics Standard sample paper 2024-25: question 21(B)

From the official CBSE sample question paper for 2024-25, section B, question 21(B), for 2 marks. Try it first; the hints and our step-by-step solution are below.

Q21(B) · 2 marks · Very short answerReal Numbers

The H.C.F of $85$ and $238$ is expressible in the form $85 m - 238$ . Find the value of $m$ .

Source: official sample paper from cbseacademic.nic.in (PDF). See it in the full Sample paper 2024-25.

Hints

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

Hint 1

First find the HCF of 85 and 238 by prime factorisation.

Hint 2

Set $85 m - 238$ equal to the HCF and solve for $m$ .

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.

$85 = 5 \times 17$ and $238 = 2 \times 7 \times 17$ , so HCF $(85, 238) = 17$ .
1 mark
$85 m - 238 = 17 \Rightarrow 85 m = 255 \Rightarrow m = 3$ .
1 mark

Answer: $m = 3$

Where the marks are

Finds HCF = 17 (1 mark)
Solves $85 m - 238 = 17$ to get $m = 3$ (1 mark)

Revise the chapter

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

Practise this chapterBoard-style questions from Real Numbers, one at a time, marked against the answer key and marking points.Back to the full paperSample paper 2024-25 (Standard): every question, by section.

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CBSE Class 10 Mathematics Standard sample paper 2024-25: question 21(B)

Hints

Step-by-step solution

Revise the chapter

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