Page 227 - Maths Skills - 7

Answers 225

8
B. 1. 2. 72.9 3. 0.09999 4. decimal fractions C. 1. (iii) 2. (i) 3. (ii)
13
17 8 17
4. (iv) 5. (v) D. 1. Painter group 2. 3. 4. E. 1. (a) 2. (a)
32 25 35
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3. (c) F. 1. 120 orange 2. ` 350 3. ` 29,400 4. 39.0625 m 2 5. ` 366.18 6. 3.44
4
7. 45.045 km/h approx. 8. 13 km
G. (a) Russia > Canada > USA > China > Brazil > Australia > India > Argentina > Kazakhstan > Algeria (b) Canada (c) 1.36 tines
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(d)
18
HOTS
7 5
1. 6 books, 4 encyclopedias 2. 3. (i) 24 (ii) 4. or
9 12

Chapter - 3: Simple Equations

Boot-up
A. 1. (iii) 2. (i) 3. (i) 4. (ii) B. 1. p 2. – 9 3. 0 4. k
C. 1. T 2. F 3. F 4. F
Exercise - 3.1
1 5 2x 2
4
2
718 (ii)
3 − (iii)
1. (i) Yes (ii) No (iii) No (iv) No 2. (i) x += 7 x += 9 3 −= 7 (iv) t −= 21
3
3
(v) 3c – 8 = 4 (vi) 9z – 9 = 54
3. (i) Nine added to a number gives 13. (ii) Four times p divided by 7 more than p is equal to 15.
(iii) Four subtracted from eight times m is equal to 16. (iv) Seven subtracted from four-fifth of a number gives zero.
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(v) Five times of a number is equal to – 20. (vi) A number divided by 3 gives .
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x
4. (i) = 6 (ii) 2x – 13 = 345 (iii) 2x – 36 = 82 (iv) 3x = 7 (v) 2x + 1 = 23
2
Exercise - 3.2
5
1. (i) p = 2 (ii) m = 7 (iii) r = 2 2. (i) b = – 4 (ii) b = – 27 (iii) v = 18 (iv) m = (v) n = 6
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5 25 1
(vi) y = 7 3. (i) m = (ii) a = 1 (iii) m = 24 (iv) n = 1 (v) b = 7 (vi) m = or 6
2 4 4
4. (i) b = – 6 (ii) a = 3 (iii) m = 24 (iv) x = – 4 (v) p = 5 (vi) x = 7
Exercise - 3.3
1. (i) s = – 4 (ii) q = 4 (iii) m = 2 (iv) x = – 2 (v) s = – 7 (vi) m = 2 (vii) x = 3 (viii) x = 7
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(ix) x = (x) x = 11 (xi) x = 5 (xii) x = –9
11
1 2 1 8 3
2. (i) x = 3 (ii) x = – 8 (iii) x = 76 (iv) x = 19 (v) x = 6 (vi) x = 54 (vii) x = (viii) y = 8
2 7 3 5 4
29 4
(ix) x = (x) x = 7
24 7
Exercise - 3.4
1. (i) 28 (ii) 11 (iii) 216 (iv) 17 2. l = 217 m, b = 213 m 3. 16, 48
4. Arjun = 219, Lalit = 73 5. 26 6. 45°, 45°, 90°, Right angled triangle
7. ` 10 notes = 50, ` 50 notes = 10
Assessment Time
A. 1. (ii) 2. (iii) 3. (ii) 4. (iii) 5. (ii) B. 1. x = 3 2. more 3. equal