Class 9 Maths Ganita Manjari Chapter 7 Exercise 7.1 Solutions

Probability is a measure of how likely an event is to happen, written on a scale from 0 to 1.
Class 9 Maths Ganita Manjari Chapter 7 Exercise 7.1 connects this scale with impossible, less likely, equally likely, more likely and certain events.

Chapter 7, The Mathematics of Maybe: Introduction to Probability Class 9, begins with everyday uncertainty: rain, school matches and lucky draws. Exercise 7.1 uses this idea to classify events on the probability scale Class 9 students learn in the first section. Class 9 Maths Ganita Manjari Chapter 7 Exercise 7.1 Solutions focus on one textbook question with four real-life events. Students rank each event between 0 and 1 and label it as impossible, less likely, equally likely, more likely or certain. The textbook explains that probability is measured from 0 for impossibility to 1 for certainty.

Key Takeaways

• Probability Scale: Probability is measured from 0 to 1.
• Impossible Event: An impossible event has probability 0.
• Certain Event: A certain event has probability 1.
• Event Ranking: Real-life events can be ranked using likelihood words before exact calculation.

Class 9 Maths Ganita Manjari Chapter 7 Exercise 7.1 Solutions Structure 2026

Class 9 Maths Ganita Manjari Chapter 7 Exercise 7.1 Solutions for Probability Scale

Exercise 7.1 has one question based on ranking events on a probability scale. The scale moves from impossible at 0 to certain at 1, with less likely, equally likely and more likely placed between them.

Q1. Rank the following events on a scale from 0 (Impossible) to 1 (Certain). Label each event: Impossible, less likely, equally likely, more likely, certain. Give reasons why you gave each event its ranking.

Each event can be ranked by checking whether it can happen, how commonly it happens, and whether it is guaranteed.

Ganita Manjari Class 9 Chapter 7 Exercise 7.1: Event Ranking Answers

The four events in this question are from everyday life. Each answer below gives a probability rank, label and reason.

Q1(i). The next Monday will come after Sunday.

This event is certain because Monday always follows Sunday in the weekly calendar.

Rank on scale:

1

Label:

Certain

Reason:

The order of days in a week is fixed.

Copy-friendly answer:

Probability = 1

Answer:

The event “The next Monday will come after Sunday” is certain.

Q1(ii). It will snow in Mumbai in July.

This event is impossible in normal weather conditions because Mumbai has a tropical coastal climate and July is part of the monsoon season.

Rank on scale:

0

Label:

Impossible

Reason:

Mumbai does not receive snowfall in July.

Copy-friendly answer:

Probability = 0

Answer:

The event “It will snow in Mumbai in July” is impossible.

Q1(iii). An elephant will walk through your classroom today.

This event is less likely because an elephant entering a classroom is extremely rare in normal school conditions.

Rank on scale:

Close to 0

Label:

Less likely

Reason:

A classroom is a controlled school space, and elephants are not expected to enter it during a normal school day.

Copy-friendly answer:

Probability is close to 0

Answer:

The event “An elephant will walk through your classroom today” is less likely.

Q1(iv). You will greet at least one friend at school tomorrow.

This event is more likely because students usually meet friends during a school day.

Rank on scale:

Close to 1

Label:

More likely

Reason:

A student normally meets classmates or friends at school.

Copy-friendly answer:

Probability is close to 1

Answer:

The event “You will greet at least one friend at school tomorrow” is more likely.

Class 9 Maths Chapter 7 Exercise 7.1 Solutions in Table Form

This table gives the complete Exercise 7.1 answer in a quick revision format.

The Mathematics of Maybe Introduction to Probability Class 9: Concepts Used in Exercise 7.1

Exercise 7.1 is based on the first idea of probability: likelihood can be described using words and then placed on a number scale. This helps students compare uncertain events before using formulas in later exercises.

Probability Scale Class 9

The probability scale shows how likely an event is.

Copy-friendly scale:

0 = Impossible

Between 0 and 1/2 = Less likely

1/2 = Equally likely

Between 1/2 and 1 = More likely

1 = Certain

The textbook uses this scale to describe impossible, less likely, even chance, more likely and certain events.

Impossible Event Probability

An impossible event cannot happen under the given conditions.

Copy-friendly result:

Probability of an impossible event = 0

Example from Exercise 7.1:

It will snow in Mumbai in July.

Certain Event Probability

A certain event is guaranteed to happen.

Copy-friendly result:

Probability of a certain event = 1

Example from Exercise 7.1:

The next Monday will come after Sunday.

Equally Likely Event Class 9

An equally likely event has the same chance of happening as not happening.

Copy-friendly result:

Probability of an equally likely event = 1/2

Example:

Getting heads on a fair coin toss.

Less Likely and More Likely Probability

Less likely events are closer to 0 on the probability scale.

More likely events are closer to 1 on the probability scale.

Copy-friendly comparison:

Less likely: 0 < Probability < 1/2

More likely: 1/2 < Probability < 1

Class 9 Maths Probability Solutions: How to Rank Events Correctly

Event ranking becomes easier when students first check whether the event is guaranteed, impossible or uncertain. Uncertain events are then placed between 0 and 1 using common sense and available evidence.

Step 1: Check for Certainty

If the event must happen, rank it as 1.

Example:

Monday after Sunday

Probability = 1

Step 2: Check for Impossibility

If the event cannot happen under normal conditions, rank it as 0.

Example:

Snow in Mumbai in July

Probability = 0

Step 3: Check for Rare Events

If the event can happen only in unusual conditions, rank it close to 0.

Example:

Elephant walking through a classroom

Probability is close to 0

Step 4: Check for Common Events

If the event usually happens, rank it close to 1.

Example:

Greeting a friend at school

Probability is close to 1

Quick Concept Table for Class 9 Maths Ganita Manjari Chapter 7 Exercise 7.1 Solutions

NCERT Solutions for Class 9 Maths Ganita Manjari Chapter 7