NCERT Class 7 Solutions: Integers (Chapter 1) Exercise 1.1 – Part 1

  • Previous

Q-1 Following number line shows the temperature in degree Celsius (°C) at different places on a particular day:

Given the number line shows temprature in degree celsius at diffrent places on a perticular day

Temprature in Degree Celsius at Different Places

Given the number line shows temprature in degree celsius at diffrent places on a perticular day

  1. Observe this number line and write the temperature of the place marked on it.

  2. What is the temperature difference between the hottest and the coldest place among the above?

  3. What is the temperature difference between Lahulspiti and Srinagar?

  4. Can we say temperature of Srinagar and Shimla taken together is less than the temperature at Shimla? Is it also less than the temperature at Srinagar?

Following figure shows operations with negative integers:

Positive and negative intergers on number line

Positive and Negative Intergers

Positive and negative intergers on number line

Rules for adding subtracting, multiplying and dividing positve and negative integers

Signs When Adding Subtracting, Multiplying and Dividing

Rules for adding subtracting, multiplying and dividing positve and negative integers

Solution:

The above scale shows temperature on a scale. The longer marks on the scale are marked at difference of 5°C each small mark is at difference of 1°C .

  1. Temperature and places are given in following table

    Table of temeratures of places
    Table describing the temperature of places

    Place

    Temperature (°C)

    Lahulspiti

    -8

    Srinagar

    -2

    Shimla

    5

    Ooty

    14

    Bengaluru

    22

  2. The hottest place is Bengaluru, with temperature

    Bengaluru=22°C

    The coldest place is Lahulspiri, with temperature

    Lahulspiri=8°C

    Diffrence=22°C(8°C)

    Diffrence=22°C+8°C

    Diffrence=30°C

  3. The temperature of Srinagar =2

    The temperature of Lahulspiri =8

    Diffrence=2°C(8°C)

    Diffrence=2°C+8°C

    Diffrence=6°C

    Note that the difference is always positive.

  4. The temperature of Srinagar and Shimla =5+(2)

    The temperature of Srinagar and Shimla =52=3

    The temperature at Shimla =5

    Since, 3<5

    Thus, temperature of Srinagar and Shimla taken together is less than the temperature at Shimla.

    Now, Temperature of Srinagar =2

    Therefore, 3>2

    No, it is not less than the temperature at Srinagar.

Q-2 In a quiz, positive marks are given for correct answers and negative marks are given for incorrect answers. If Jack’s scores in five successive rounds were 25,5,10,15and10 , what was his total at the end?

Solution: If Jack’s scores in five successive rounds are 25,5,10,15and10 His total marks are 25+(5)+(10)+15+10

=2515+25

=35

Thus, Jack got 35 marks in the quiz.

Q-3 At Srinagar temperature was 5 on Monday and then it dropped by 2 on Tuesday. What was the temperature of Srinagar on Tuesday? On Wednesday, it rose by 4. what was the temperature on this day?

Solution:

  • On Monday, temperature at Srinagar = 5

  • On Tuesday, temperature dropped = 2

  • ∴Temperature on Tuesday =52=7

  • On Wednesday, temperature rose up = 4

  • ∴Temperature on Wednesday =7+4=3

  • Thus, temperature on Tuesday and Wednesday was 7 and 3 respectively.

Explore Solutions for Mathematics

Sign In