# Discrete Mathematics Questions and Answers – Number Theory and Cryptography – Rules of Exponents

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This set of Basic Discrete Mathematics Questions and Answers focuses on “Number Theory and Cryptography – Rules of Exponents”.

1. For some number b, (1b)-n is equal to _________
a) -bn
b) nb
c) bn
d) none of the mentioned

Explanation: b-1 reciprocal of b.

2. If ab = 1, where a and b are real numbers then?
a) a = b-1
b) b = a
c) a = b = 2
d) none of the mentioned

Explanation: This means that a is inverse of b or b is inverse of a.

3. If a is a real number than a0 is defined as _________
a) 0
b) a
c) 1
d) -1

Explanation: Any number to the power zero is one.

4. For some number a, b and c, ca x cb is equal to _________
a) ca-b
b) ca+b
c) c
d) none of the mentioned

Explanation: If base are same then exponenents powers are added.

5. For some number a, b and c, ca/cb is equal to _________
a) ca-b
b) ca+b
c) c
d) None of the mentioned

Explanation: If base are same then exponenents powers are added, 1/cb = c-b.

6. State whether the given statement is true or false.
Exponentiation is commutative.
a) True
b) False

Explanation: Ab is not equal to bA, exponentiation is not commutative.

7. State whether the given statement is true or false.
Exponentiation is associative.
a) True
b) False

Explanation: Exponentiation is not associative.

8. If 2a-b = 1 then the value of a-b is equal to _________
a) 1
b) 0
c) 2
d) none of the mentioned

Explanation: 1 = 20, so a-b = 0.

9. For some number a, b and c, ac x bc is equal to _________
a) (ab)c
b) (ac)b
c) (cb)a
d) None of the mentioned

Explanation: If power are same then bases are multiplied.

10. If 0a is not equal to zero then which of the values a cannot take _________
a) 1
b) 2
c) -1
d) 0

Explanation: a0 = 1, for any real number.

Sanfoundry Global Education & Learning Series – Discrete Mathematics.

To practice basic questions and answers on all areas of Discrete Mathematics, here is complete set of 1000+ Multiple Choice Questions and Answers.