NCERT Class 7 Mathematics First Chapter Integers Exercise 1.2 Solutions

NCERT Class 7 Mathematics First Chapter Integers Exercise 1.2 Solutions

EXERCISE 1.2

(1) Write down a pair of integers whose:

(a) Sum is –7               

Solution: (- 4) + (- 3) = – 7 or (- 9) + 2 = – 7

(b) Difference is –10

Solution: – 20 – (- 10) = – 10 or – 5 – 5 = – 10

(c) Sum is 0

Solution: – 10 – (- 10) = 0 or 5 – 5 = 0

(2) (a) Write a pair of negative integers whose difference gives 8.

Solution: – 2 – (- 10) = 8

(b) Write a negative integer and a positive integer whose sum is –5.

Solution: – 10 + 5 = – 5

(c) Write a negative integer and a positive integer whose difference is –3.

Solution: – 4 + 1 = – 3

(3) In a quiz, team A scored – 40, 10, 0 and team B scored 10, 0, – 40 in three successive rounds. Which team scored more? Can we say that we can add integers in any order?

Solution: Total score of team A = – 40 + 10 + 0 = – 30

Total score of team B = 10 + 0 – 40 = – 30

Hence, the score is of both team are equal.

Yes, we can add integers in any order.

(4) Fill in the blanks to make the following statements true:

(i) (–5) + (– 8) = (– 8) + (- 5)

(ii) –53 + 0 = –53

(iii) 17 + (- 17) = 0

(iv) [13 + (– 12)] + (- 7) = 13 + [(–12) + (–7)]

(v) (– 4) + [15 + (–3)] = [– 4 + 15] + (- 3)