SCERT AP 7th Class Maths Solutions Pdf Chapter 1 Integers Ex 1.2 Textbook Exercise Questions and Answers.

## AP State Syllabus 7th Class Maths Solutions 1st Lesson Integers Exercise 1.2

Question 1.

Calculate the following,

(i) (- 96) ÷ 16

Answer:

(- a) ÷ b = – \(\frac{a}{b}\)

= \(\frac{-96}{16}\) = – 6

(ii) 98 ÷ (- 49)

Answer:

a ÷ (- b) = – \(\frac{a}{b}\)

= \(\frac{98}{-49}\) = – 2

(iii) (- 51) ÷ 17

Answer:

(- a) ÷ b = – \(\frac{a}{b}\)

= \(\frac{-51}{17}\) = – 3

(iv) 38 ÷ (- 19)

Answer:

a ÷ (- b) = – \(\frac{a}{b}\)

= \(\frac{38}{-19}\) = – 2

(v) (- 80) ÷ 20

Answer:

(- a) ÷ b = – \(\frac{a}{b}\)

= \(\frac{-80}{20}\) = – 4

(vi) (- 150) ÷ (- 25)

Answer:

(- a) ÷ (- b) = – \(\frac{-a}{-b}\) = \(\frac{a}{b}\)

= \(\frac{-150}{-25}\) = \(\frac{150}{25}\) = – 6

(vii) (- 600) ÷ 60

Answer:

(- a) ÷ b = – \(\frac{a}{b}\)

= \(\frac{-600}{60}\)

= – 10

(viii) (-54) ÷ 9

Answer:

(- a) ÷ b = – \(\frac{a}{b}\)

= \(\frac{- 54}{9}\)

= – 6

(ix) 130 ÷ 65

Answer:

a ÷ b = \(\frac{a}{b}\)

= \(\frac{130}{65}\)

= 2

(x) (- 315) ÷ ( -315)

Answer:

(- a) ÷ (- b) = \(\frac{-a}{-b}\) = \(\frac{a}{b}\)

= \(\frac{-315}{-315}\)

= \(\frac{315}{315}\)

= 1

Question 2.

The product of two integers is – 165. If one number is – 15, find the other integer.

Answer:

Given one number a = – 15

Other number b = ?

Product of two numbers = (- 165)

a × b = – 165

(- 15) × b = – 165

b = (- 165) × (- 15)

Other number b = 11

Question 3.

Because of Covid-19 a company lockdown for 6 months and got loss of ₹1,32,000 in the year 2020. Find the average loss of each month.

Answer:

Given loss of 6 months = ₹ 1,32,000

Average loss of each month = 1,32,000 ÷ 6

Average loss of each month = ₹ 22,000

Question 4.

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 ?

Answer:

The temperature at 12 noon = 10°C above zero.

The temperature is decreasing at 2°C per hour 8°C below zero = – 8°C

So, total temperature falls 2°C in every one hour.

Therefore, to decrease 18°C, time taken

= 18/2 = 9 hrs.

Present time is 12 noon, so, the time when the temperature at 12 midnight will be

= (- 8° C) + (- 2° C × 3 hrs.)

= (- 8° C) + (- 6° C)

= 160

So, at 12 midnight the temperature will be – 14°C

Question 5.

A green grocer earns a profit of ₹ 7 per kg of tomato and got loss of ₹ 4 per kg of brinjal by selling. On Monday he gets neither profit nor loss,.if he sold 68 kgs of tomato. How many kgs of brinjal did he sell ?

Answer:

Given profit per kg of tomato = ₹ 7

Loss per kg of brinjal = ₹ 4

Weight of tomatoes sold = 68 kgs

Let number of kgs of tomato be x kg.

Number of kgs of brinjals be y kg.

7x – 4y = 0

7 × 68 – 4y = 0

– 4y = – 7 × 68

y = \(\frac{-7 \times 68}{-4}\)

∴ Weight of brinjals sold = + 7 × 17

= + 119 kgs.

Question 6.

In a test, each correct answer carry + 3 marks and incorrect answer – 1 mark, Sona attempted all the questions and scored + 20 marks though she got 10 correct answers.

(i) How many incorrect answers did she attempt ?

(ii) How many questions were given in the test ?

Answer:

Given marks for every correct answer = + 3

Given marks for every incorrect answer = – 1

No. of correct answer questions = 10

Total marks gained on correct answer questions = 10 × (+3) = + 30

(i) No. of incorrect answer questions = x

Total marks gained on incorrect answer questions = y × (-1) = – y.

Marks scored by Sona

⇒ + 30 + (- y) = + 20

⇒ – y = + 20 – 30

⇒ – y = – 10

⇒ y = 10

∴ No. of incorrect answers Sona attempts =10

(ii) Number of questions given in the test = No. of correct answer questions + No. of incorrect answer questions.

= 10 + 10 = 20 questions.

Question 7.

Write 5 pairs of integers (a, b) such that a ÷ b = -4.

(Ex : (12, – 3) because 12 + (-3) = -4)

Answer:

(i) (-16, +4) because (- 16) ÷ 4 = -4

(ii) (20, -5) because 20 ÷ (-5) = – 4

(iii) (—8, 2) because (-8) ÷ 2 =- 4

(iv) (24, -6) because 24 ÷ (-6) = – 4

(v) (-36, 9) because (-36) ÷ 9 = – 4

(OR)

a | b | a ÷ b = – 4 |

(-16) | 4 | (-16) ÷ 4 = – 4 |

20 | (-5) | 20 ÷ (-5) = – 4 |

8 | 2 | (- 8) ÷ 2 = – 4 |

24 | (-6) | 24 ÷ (- 6) = – 4 |

-36 | 9 | (-36) ÷ 9 = – 4 |