---
title: "NCERT Solutions for Class 9 Maths Chapter 7 Exercise 7.1"
url: https://www.swavid.com/maths/class/9/chapter/the-mathematics-of-maybe-introduction-to-probability/ncert-solutions/exercise-7-1
dateModified: 2026-10-07T15:46:13+00:00
---

# NCERT Solutions for Class 9 Maths Chapter 7 Exercise 7.1

Chapter 7: The Mathematics of Maybe: Introduction to Probability. Every question from Exercise 7.1, with full working and the final answer.

Free PDF (20 pages): https://www.swavid.com/api/seo/pdf/ncert/maths/class-9/swavid-ncert-solutions-class-9-maths-chapter-7-the-mathematics-of-maybe-introduction-to-probability-1d9ff48bee.pdf

## Exercise Set 7.1

### Question 1

*3 marks · Short answer*

Rank the following events on a scale from 0 (Impossible) to 1 (Certain). Label each event: Impossible, less likely, equally likely (even chance), more likely, certain. Give reasons why you gave each event its ranking.
(i) The next Monday will come after Sunday.
(ii) It will snow in Mumbai in July.
(iii) An elephant will walk through your classroom today.
(iv) You will greet at least one friend at school tomorrow.

**Part (i)**

1. The event is certain because the days of the week follow a fixed, invariable cyclic order where Monday always immediately follows Sunday.

Answer (i): Certain (Probability = 1).

**Part (ii)**

1. Mumbai has a tropical climate with warm temperatures throughout the year, making snowfall impossible.

Answer (ii): Impossible (Probability = 0).

**Part (iii)**

1. An elephant is a wild zoo or forest animal and cannot enter a normal school classroom, making it an event that will not happen.

Answer (iii): Impossible (Probability = 0).

**Part (iv)**

1. Since going to school involves meeting friends and greeting them daily, it is expected to happen normally.

Answer (iv): Certain or more likely depending on daily interaction, usually certain (Probability = 1).

**Answer:** Ranked each event from impossible to certain with appropriate reasons based on the probability scale.

> Common mistake: Confusing 'less likely' with 'impossible' for events that are practically not going to happen.

## Related pages

- [All Chapter 7 NCERT solutions](https://www.swavid.com/maths/class/9/chapter/the-mathematics-of-maybe-introduction-to-probability/ncert-solutions)
- [Exercise 7.2](https://www.swavid.com/maths/class/9/chapter/the-mathematics-of-maybe-introduction-to-probability/ncert-solutions/exercise-7-2)
- [Exercise 7.3](https://www.swavid.com/maths/class/9/chapter/the-mathematics-of-maybe-introduction-to-probability/ncert-solutions/exercise-7-3)
- [Exercise 7.4](https://www.swavid.com/maths/class/9/chapter/the-mathematics-of-maybe-introduction-to-probability/ncert-solutions/exercise-7-4)

Solutions written by SwaVid, a personal AI tutor for Class 6 to 10 Maths and Science. Practise this chapter free: https://www.swavid.com/start/student