Page 335 - Start Up Mathematics_7

Answers

Chapter 1 Integrating Fun and Facts—The Barrel Operators
(b) 2 4 2 –4 2
Try It Out!
(c) –5 –15 10 –2 0
1 –10 0 Review Exercises
–4 –3 –2 Multiple Choice Questions
–6 4 –7 1. c 2 a 3. c 4. d
Exercise 1.1 5. d 6. a 7. c
1. (a) 29 (b) 12 (c) –24 (d) 24 Solve Mentally
2. (a) 1 (b) –6 (c) 7 (d) 3
3. (a) –13°C (b) –130 m (c) +90 m (d) +50,000 rupees True or False
1. True 2. False 3. False 4. False 5. True
+ –6 –3 –2 –1 0 2 5 7
6. False 7. True
4. 1 –5 –2 –1 0 1 3 6 8
Fill in the Blanks
3 –3 0 1 2 3 5 8 10 1. Negative 2. –a 3. –6 4. infinite
8 2 5 6 7 8 10 13 15 5. modulus 6. > 7. < 8. 7 9. 2

–1 –7 –4 –3 –2 –1 1 4 6 Answer in One Word or a Line
–5 –11 –8 –7 –6 –5 –3 0 2 1. 3, –3 2. 0 3. Positive
4. Negative 5. Negative 6. 0
5. (a) 219, 34, –45, –890 (b) 678, 432, –675, –980 6. 6°C
7. 20.5°C 8. 6,550 m 9. Reshma 10. 8 attempts Let’s Evaluate
1. (a) –192 (b) 0 (c) 1,200
Exercise 1.2
Note: Question number 1 to 3 can have infinite answers of 2. (a) –51 (b) 100 3. 8.5°C
which one is given. 4. (a) Profit of ` 21,000 (b) 1,000 white cement bags
1. (a) –9, 0 (b) –3, 15 (c) 3, –4 5. (a) 55 (b) 1
2. –18 and 3 3. 10 and –1 6. (a) 76°C (b) 25°C (c) 50°C
4. Both teams scored the same.
Thinking Skills
Exercise 1.3
1. ` 1,550
1. (a) 84 (b) –64 (c) –99 (d) 30 (e) 0
2. decrease of 2,000 feet; 18,000 feet 3. 31 marbles
2. (a) –48 (b) 140 (c) –378 (d) 0 (e) 400
4. (a) 5°F (b) 104°F (c) –40°F
3. (a) –24 (b) –161 (c) –60 (d) 120 (e) –1,600
5. (a) 6 ÷ 4 is not an integer (b) (8 ÷ 2) ÷ 4 ≠ 8 ÷ (2 ÷ 4)
4. (a) 50 (b) 17 5. Profit ` 1,47,200 (c) 6 – 2 ≠ 2 – 6 (d) 4 ÷ (8 + 4) ≠ (4 ÷ 8) + (4 ÷ 4)
Exercise 1.4 (Note: Variable answers are possible in Q. 5)
1. (a) –15 (b) 3 (c) –2 (d) 0 6. (a) 80°C (b) 32°C
2. (a) –9 (b) –60 (c) –23 (d) –11 (e) –76 7. (a) INJ-T20, INJ-58R
3. (a) True (b) False (c) False (d) True (b) INJ-T20

Exercise 1.5 (c) INJ-F308
1. (a) –23 (b) 10 (c) 10 (d) 20 (e) 29 Values and Life Skills
2. (a) 63 ÷ {1 + (3 + 5)} (b) 3 × {(16 – 4) – 2} 1. 30 min 2. Peter had to pay ` 300
1
(c) (60 + 30) – 18 (d) 80 ÷ {4 × (2 + 3)} Exemplar Problems
3 1. b 2. b 3. minus 4. False 5. False
(e) 9(3 + 4 + 5) 6. 725 years 7. (a) 5,300 (b) –1,360