## ML Aggarwal Class 7 Solutions for ICSE Maths Chapter 1 Integers Ex 1.2

Question 1.

Write a pair of integers whose:

(i) sum is -3

(ii) difference is -5

(iii) difference is 4

Solution:

Pair of integers whose,

(i) sum is -3 = -6, 3 (-6 + 3 = -3)

(ii) difference is -5 = -2, 3 (-2 – 3 = -5)

(iii) difference is 4 = -3, -7 [-3 – (-7) = -3 + 7 = 4]

Question 2.

(i) Write a pair of negative integers whose difference is 5.

(ii) Write a negative integer and a positive integer whose sum is -8.

(iii) Write a negative integer and a positive integer whose difference is -3.

Solution:

(i) Let two negative integers whose difference is 5 be -7, -12.

Now the difference is -7 – (-12)

= -7 + 12 = 5

(ii) Let two integers one negative and other positive but sum is -8 are -13, 5

= -13 + 5 = -8

(iii) Let two integer, one negative and other positive whose difference is -3 be -1, 2

Difference = -1 – (2) = -1 – 2 = -3

Question 3.

Write two integers which are smaller than -5 but their difference is greater than -5.

Solution:

Let two integer which are smaller than -5 but their difference is greater than -5

= -6, -8 as -6 – (-8)

= -6 + 8

= 2 > -5

Question 4.

In a quiz, team A scored -30, 20, 0 and team B scored 20, 0, -30 in three successive rounds. Which team socred more? Can we

say that we can add integers in any order?

Solution:

In a quiz,

Team A scored -30, 20, 0 and

Team B scored 20, 0, -30 in three rounds

Sum of scores of A team = -30 + 20 + 0 = -10

Sum of scores of B team = 20 + 0 – 30 = -10

The scores of both the team are equal i.e. -10

Yes, by adding the scores in any order, the result will be the same.

Question 5.

Find the sum of integers -72, 237, 84, 72, -184, -37.

Solution:

Sum of integers -72, 237, 84, 72, -184, -37

= -72 + 237 + 84 + 72 + -184 + -37

= 237 + 84 + 72 + (-72 – 184 – 37)

= (393) + (-293)

= 393 – 293

= 100