Exponents and Powers Worksheet-9

Exponents and Powers Worksheet-9

1. The value of (–8) × (–8) × (–8) × (–8) × (–8) × (–8) × (–8) × (–8) × (–8) × (–8) is

(a) –2(8)⁵          (b) –(2)¹⁶           (c) –(4)⁸             (d) all of these

2. Express 0.0084 in scientific notation.

(a) 84 × 10                                     (b) 8.4 × 10^–3

(c) 0.84 × 10^–2                              (d) 8.4 × 10^–5

3. If = 0.008, then (0.25)^y will be

(a) 1                     (b) 0.25              (c) 0.0625         (d) 0.125

4. If , then x = ?

(a)                  (b) –2                 (c) 2                    (d)

5. Which of the following number is in the scientific notation?

(a) 1.26 × 10^–5 m                          (b) 15.75 × 10³ km

(c) 0.18 × 10^–7 km                        (d) 0.0013 × 10^–8 km

6. The value of   is

(a) a^–1 × b^–1       (b)                 (c) a¹ b^–1             (d) ab

(a)                  (b) 16                  (c)                  (d) –16

8. If = 81, then n = ?

(a) 2                    (b) 4                    (c) 6                    (d) 8

9. If 8^x–1 = 2^x+3, then x is

(a) 2                    (b) 4                    (c) 1                     (d) 3

10. Cube of  is

(a)           (b)          (c)                  (d)

(a)                   (b)                 (c)                    (d)

12. The value of  is

(a)                 (b)                 (c)                 (d)

13. If  then x =

(a) 3                    (b) 2                    (c) 1                     (d) 0

14. If  then a is

(a) –1                  (b) 0                    (c) 1                     (d) 2

15. The number which is multiplied by (–8)^–1 to obtain a product equal to 10^–1

(a)                 (b)                 (c)                 (d)

16. By what number should (–15)^–1 be divided so that the quotient is (–5)^–1?

(a) 3^–1                 (b) 3                    (c) 2                    (d) 2^–1

17. The value of a^b – b^a, if a = 3, b = 7 is

(a) 1825             (b) 1840             (c) 1844             (d) 1850

18. The 3^x = 500, then the value of 3^x–2 is

(a)               (b)            (c)               (d)

19. The value of  is

(a)              (b)                 (c)                 (d)

20. By what number should we multiply 4^–3 so that the product may be equal to 64?

(a) 4⁵                   (b) 2¹²                 (c) 2⁶                   (d) 2⁸

Answer Key:

(1)-(d); (2)-(b); (3)-(b); (4)-(b); (5)-(a); (6)-(d); (7)-(a); (8)-(d); (9)-(d); (10)-(a); (11)-(b); (12)-(a); (13)-(a); (14)-(c); (15)-(a); (16)-(a); (17)-(c); (18)-(c); (19)-(a); (20)-(b)