# NCERT Class 7 Mathematics Chapter 15 Finding the Unknown Solutions: In-Text and Exercise Questions Explained | SwaVid

This document contains questions and step-by-step solutions from NCERT Class 7 Mathematics textbook "Ganita Prakash-II", Chapter 7: "Finding the Unknown...

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# Finding the Unknown

## Find the gaps before this chapter finds them for you.

## Related chapters

Chapter 15 · Class 7 Mathematics

This document contains questions and step-by-step solutions from NCERT Class 7 Mathematics textbook "Ganita Prakash-II", Chapter 7: "Finding the Unknown". The questions include both in-text problems and end-of-chapter exercises, transcribed as accurately as possible from reliable online sources referencing the official NCERT textbook.

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In-text Questions

Answer: Jasmine's arrangement is at position 49. It is not possible to make an arrangement with exactly 200 sticks.

Exercise Questions

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Source

- Identify the pattern for the number of matchsticks: The arrangement at position 'n' has 2n + 1 matchsticks.
- For Jasmine's arrangement with 99 sticks, set up the equation: 2n + 1 = 99.
- Subtract 1 from both sides: 2n = 99 - 1.
- Simplify: 2n = 98.
- Divide by 2: n = 98 / 2.
- Calculate n: n = 49. So, Jasmine's arrangement is at position 49.
- For the second part, check if 200 sticks are possible. Set up the equation: 2n + 1 = 200.
- Subtract 1 from both sides: 2n = 200 - 1.
- Simplify: 2n = 199.
- Divide by 2: n = 199 / 2.
- Calculate n: n = 99.5.
- Since 'n' must be a whole number (representing a position number), it is not possible to make an arrangement with exactly 200 sticks.
- NCERT Class 7 Mathematics textbook: Ganita Prakash-II : Chapter 15: Finding the Unknown

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