1. At Srinagar temperature was – 5°C on Monday and then it dropped by 2°C on Tuesday. What was the temperature of Srinagar on Tuesday? On Wednesday, it rose by 4°C. What was the temperature on this day?

2. A plane is flying at the height of 5000 m above the sea level. At a particular point, it is exactly above a submarine floating 1200 m below the sea level. What is the vertical distance between them?

3. Mohan deposits Rs 2,000 in his bank account and withdraws Rs 1,642 from it, the next day. If withdrawal of amount from the account is represented by a negative integer, then how will you represent the amount deposited? Find the balance in Mohan’s account after the withdrawal.

4. Rita goes 20 km towards east from a point A to the point B. From B, she moves 30 km towards

west along the same road. If the distance towards east is represented by a positive integer then, how will you represent the distance travelled towards west? By which integer will you represent her final position from A?

5. Write a pair of integers whose sum gives

(a) a negative integer

(b) zero

(c) an integer smaller than both the integers.

(d) an integer smaller than only one of the integers.

(e) an integer greater than both the integers.

6. Write a pair of integers whose difference gives

(a) a negative integer.

(b) zero.

(c) an integer smaller than both the integers.

(d) an integer greater than only one of the integers.

(e) an integer greater than both the integers.

7. Write down a pair of integers whose

(a) sum is –3

(b) difference is –5

(c) Difference is 2

(d) sum is 0

8. Write down a pair of integers whose:

(a) sum is –7

(b) difference is –10

(c) sum is 0

9. Write a pair of negative integers whose difference gives 8.

10. Write a negative integer and a positive integer whose sum is –5.

11. Write a negative integer and a positive integer whose difference is –3.

12. Find: 4 × (– 8), 8 × (–2), 3 × (–7), 10 × (–1) using number line.

13. Verify (–30) × [13 + (–3)] = [(–30) × 13] + [(–30) × (–3)]

14. In a class test containing 15 questions, 4 marks are given for every correct answer and (–2) marks are given for every incorrect answer. (i) Gurpreet attempts all questions but only 9 of her What will be her score?

**15.**An elevator descends into a mine shaft at the rate of 5 metre per minute. What will be its position after one hour? If it begins to descend from 15 m above the ground, what will be its position after 45minutes?

**16.**A certain freezing process requires that room temperature be lowered from 40°C at the rate of 5°C every hour. What will be the room temperature 10 hours after the process begins?

**17.**In a test (+5) marks are given for every correct answer and (–2) marks are given for every incorrect answer.

(i) Radhika answered all the questions and scored 30 marks though she got 10 correct answers.

(ii) Jay also answered all the questions and scored (–12) marks though he got 4 correct answers. How many incorrect answers had they attempted?

**18.**A shopkeeper earns a profit of Re 1 by selling one pen and incurs a loss of 40 paise per pencil while selling pencils of her old stock.

(i) In a particular month she incurs a loss of Rs 5. In this period, she sold 45 pens. How many pencils did she sell in this period?

(ii) In the next month she earns neither profit nor loss. If she sold 70 pens, how many pencils did she sell?

**19.**The temperature at 12 noon was 10°C above zero. If it decreases at the rate of 2°C per hour until midnight, at what time would the temperature be 8°C below zero? What would be the temperature at mid-night?

**20.**An elevator descends into a mine shaft at the rate of 6 m/min. If the descent starts from 10 m above the ground level, how long will it take to reach – 350 m.

**21.**Evaluate each of the following:

(a) (–30) ÷ 10 (b) 50 ÷ (–5) (c) (–36) ÷ (–9)

(d) (– 49) ÷ (49) (e) 13 ÷ [(–2) + 1] (f ) 0 ÷ (–12)

(g) (–31) ÷ [(–30) + (–1)]

(h) [(–36) ÷ 12] ÷ 3 (i) [(– 6) + 5)] ÷ [(–2) + 1]

**22.**Find the product, using suitable properties:

(a) 26 × (– 48) + (– 48) × (–36) (b) 8 × 53 × (–125)

(c) 15 × (–25) × (– 4) × (–10) (d) (– 41) × 102

(e) 625 × (–35) + (– 625) × 65 (f) 7 × (50 – 2)

(g) (–17) × (–29) (h) (–57) × (–19) + 57

**23.**Verify the following:

(a) 18 × [7 + (–3)] = [18 × 7] + [18 × (–3)]

(b) (–21) × [(– 4) + (– 6)] = [(–21) × (– 4)] + [(–21) × (– 6)]

**24.**A cement company earns a profit of Rs 8 per bag of white cement sold and a loss of Rs 5 per bag of grey cement sold.

(a) The company sells 3,000 bags of white cement and 5,000 bags of grey cement in a month. What is its profit or loss?

(b) What is the number of white cement bags it must sell to have neither profit nor loss, if the number of grey bags sold is 6,400 bags.

**25.**Find each of the following products:

(i) (–18) × (–10) × 9 (ii) (–20) × (–2) × (–5) × 7 (iii) (–1) × (–5) × (– 4) × (– 6)

MCQ’S

1. In addition and subtraction of two integers , sign of the answer depends upon

(a) Smaller number (b) Their difference

(c) Their sum (d) Greater numerical value

2. Sum of two negative number is always

(a) Positive (b) Negative (c) 0 (d) 1

3. Sum of two Positive number is always

(a) Negative (b) Positive (c) 1 (d) 0

4. Identify the property used in the following:

2 x 13 + 8 x 13 = ( 2+8 ) x 13

(a) Commutative (b) Closure (c) Associative (d) Distributive

5. Which number is multiplicative identity for the whole numbers

(a) 0 (b) 1 ( c) 2 (d) 3

6. Which property is reflected in the following? 7 x 5 = 5 x 7

(a) Closure (b) Commutative (c) Associative (d) Distributive

7. Which of the following statement is true

(a) 7 ÷ 0 = 7 (b) 7 ÷ 0 = 0 (c) 7 ÷ 0 = 0 ÷ 7 (d) 0 ÷ 7 = 0

8. Product of two negative integers is always

(a) Always negative (b) Always positive

(c) Either positive or negative (d) 0

9. The integer whose product with – 1 is – 40 is

(a) 20 (b) – 20 (c) – 40 (d) 40

10. Absolute value of – 11 is

(a) – 10 (b) 10 (c) 11 (d) 0