Anwers

308
MATHEMATICS
3. (i) False; 10 × 10 11 = 10 12 and (100) 11 = 10 22 (ii) False; 2 3 = 8, 5 2 = 25
(iii) False; 6 5 = 2 5 × 3 5 (iv) True; 3 0 = 1, (1000) 0 = 1
4. (i) 2 8 × 3 4 (ii) 2 × 3 3 × 5 (iii) 3 6 × 2 6 (iv) 2 8 × 3 5. (i) 98 (ii)
4
5t
8
(iii) 1
EXERCISE 13.3
1. 279404 = 2 × 10 5 + 7 × 10 4 + 9 × 10 3 + 4 × 10 2 + 0 × 10 1 + 4 × 10 0
3006194 = 3 × 10 6 + 0 × 10 5 + 0 × 10 4 + 6 × 10 3 + 1 × 10 2 + 9 × 10 1 + 4 × 10 0
2806196 = 2 × 10 6 + 8 × 10 5 + 0 × 10 4 + 6 × 10 3 + 1 × 10 2 + 9 × 10 1 + 6 × 10 0
120719 = 1 × 10 5 + 2 × 10 4 + 0 × 10 3 + 7 × 10 2 + 1 × 10 1 + 9 × 10 0
20068 = 2 × 10 4 + 0 × 10 3 + 0 × 10 2 + 6 × 10 1 + 8 × 10 0
2. (a) 86045 (b) 405302 (c) 30705 (d) 900230
3. (i) 5 × 10 7 (ii) 7 × 10 6 (iii) 3.1865 × 10 9 (iv) 3.90878 × 10 5
(v) 3.90878 × 10 4 (vi) 3.90878 × 10 3
4. (a) 3.84 × 10 8 m (b) 3 × 10 8 m/s (c) 1.2756 × 10 7 m (d) 1.4 × 10 9 m
(e) 1 × 10 11 (f) 1.2 × 10 10 years (g) 3 × 10 20 m (h) 6.023 × 10 22
(i) 1.353 × 10 9 km 3 (j) 1.027 × 10 9
1.
EXERCISE 14.1
(a) (b) (c)
(d) (e) (f)