Page 316 - ICSE Math 7

Exercise 21.2 Exercise 22.2
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1. (a) 15 cm (b) 24 cm (c) 6 cm 2. 12 cm 1. (a) Favourite sport of students (b) cricket
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3. (a) 48 cm (b) 4 cm 4. 24 cm (c) Hockey and badminton
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5. (a) 27 cm (b) 4.5 cm 6. 40 m 7. 36 m 8. 420 m 2 2. (a) March (b) February (c) 30
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9. 69 cm 10. 50 cm 11. 79 cm 2 3. (a) Gaurav (b) Priti and Sarika
Exercise 21.3 (c) Yes, sarika has lost the maximum marks. Priti has lost
1. (a) 132 mm (b) 44 cm the maximum percentage of marks.
1 4. (a) Getting admission in a professional college and
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2. (a) 1,257 cm (b) 1,386 cm 3. 6.3 cm 4. 4 : 5 participate in math olympaid
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5. (a) 1,386 m (b) ` 2,640 6. 14 cm (b) Getting admission in a professional college
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7. 300 revolutions 8. 1 : 9 9. 484 cm 10. 37.68 cm 2 (c) Getting admission in a professional college and join
11. 4 : 5 an educational club.
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12. (a) 50 m (b) 12.56 m (c) 37.44 m (d) 12.56 m Mental Maths
1. (a) (ii) (b) (iii) (c) (i) (d) (i) (e) (iii)
Mental Maths
1. (a) (i) (b) (iv) (c) (ii) (d) (iii) (e) (iii) (f) (iv) 2. (a) False (b) True (c) False (d) True
2. (a) True (b) True (c) False (d) False (e) True (e) False (f) True
(f) False (g) False (h) True (i) False 3. (a) 3, 2.5 (b) median (c) 50 (d) 60 (e) frequency
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3. (a) 16 cm (b) 9 cm (c) square units, unit (f) 50
(d) inscribed, less (e) p Practice Time
1. (a) 49.5 (b) 50.5 (c) 25 2. Increase by 1.75 years
Practice Time
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1. 42 cm 2. 15.25 cm 2 3. 31 4. (a) median (b) mode (c) mean
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3. 356 cm 4. 1,044 tiles, ` 24,012 5. 2, 3, 4, 4, 5, 6; No
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5. 72 cm 6. 112 cm ; 60 cm 7. 3.375 m 2 6. (a) 10 hours
(b) Median = 12 hours
Think Smart Range = 11 hours
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1. area (P) = 31.5 cm ; area (Q) = 35 cm Average mean = 12.25 hours
area (R) = 76.5 cm 2
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2. Area of shaded region in all cases = 182 cm , because in Chapter 23
each case required area is area of rectangle minus area Exercise
of circle. 1. (a) most likely (b) equally likely (c) equally likely
3. 280 cm (d) impossible (e) certain (f) not likely
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Chapter 22 2. (a) 0 (b) 12 (c) 15 (d) 1 (e) (f) 1
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Exercise 22.1 3. (a) (b) (c) 15 4. (a) HH, HT, TH, TT
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1. (a) 20 marks (b) 37 marks (c) 36 marks (d) 34 marks (b) HT, TH, TT (c) HT, TH (d) ;
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2. (a) 20.5 mm (b) 6.5 mm (c) 3 days 4 4
5. (a) 2 (b) 2 (c) 1 (d) 4
3. (a) Time (x ) Frequency (f ) Tally marks 11 11 11 11
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10 2 6. (a) (b) 1 (c) (d) 1 (e) 1
13 2 2 13 4 13 52
19 4 Mental Maths
20 1 1. (a) (iii) (b) (iv) (c) (i) (d) (iii) (e) (i)
25 1 (f) (ii) (g) (i) (h) (i) 2. (a) True (b) False
26 6 (c) True (d) True (e) True (f) True (g) False
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28 1 3. (a) impossible (b) 0, 1 (c) sample space (d)
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30 1 (e) 1 (f) equally likely (g) event (h) equal
31 2 Practice Time
(b) longest : 31 min; shortest : 10 min; range = 21 min 1. (a) R (b) T (c) P (d) Q (e) S
(c) mean = 22.15, median = 25.5, mode = 26 (d) mean 1 1 1 1
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4. 12 5. 53 kg 2. (a) (b) (c) 13 (d) 26
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