Calculate mode of the following distribution: Class 5-10 10-15 15-20 20-25 25-30 30-35 --- --- --- --- --- --- --- Frequency 5 6 15 10 5 4

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

CBSE Class 10 Mathematics Basic sample paper 2024-25: question 25

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

Q25 · 2 marks · Very short answerStatistics

Calculate mode of the following distribution:

Class	5-10	10-15	15-20	20-25	25-30	30-35
Frequency	5	6	15	10	5	4

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

The modal class is the class with the highest frequency.

Hint 2

Use Mode $= l + \frac{f _{1} - f _{0}}{2 f _{1} - f _{0} - f _{2}} \times h$ , where $f_{0}$ and $f_{2}$ are the frequencies of the neighbouring classes.

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.

The highest frequency is 15, so the modal class is 15–20.
Here $l = 15$ , $h = 5$ , $f_{1} = 15$ , $f_{0} = 6$ , $f_{2} = 10$ .
½ mark
Mode $= l + (\frac{f _{1} - f _{0}}{2 f _{1} - f _{0} - f _{2}}) \times h = 15 + (\frac{15 - 6}{30 - 6 - 10}) \times 5$
1 mark
$= 15 + \frac{45}{14} = 15 + 3.21 = 18.21$ (approx.)
½ mark

Answer: Mode ≈ 18.21

Where the marks are

Identifies the modal class 15–20 (½ mark)
Correct substitution in the mode formula (1 mark)
Mode ≈ 18.21 (½ mark)

Revise the chapter

Chapter: Statistics (notes, formulas, where marks are lost and every past question)
Topic: Mode of Grouped Data

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

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CBSE Class 10 Mathematics Basic sample paper 2024-25: question 25

Hints

Step-by-step solution

Revise the chapter

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