Page 27 - Mathematics Class - X

Viva-Voce

1. What is a sequence?
Ans. A sequence is an arrangement of numbers in a definite order according to a specific rule.

2. Define common difference in an AP.
Ans. In an AP, each term is obtained by adding a fixed number 'd' to the preceding term.
3. What do we mean by terms of a sequence?

Ans. The various numbers occurring in a sequence are called its terms.
4. What is the condition for a sequence to be an AP?

Ans. There should be equal difference between any two consecutive terms.
5. What is the formula for nth term of an AP?
Ans. The formula for nth term of an AP is T = a + (n – 1)d.
n

MCQs

1. In sequence 3, 5, 7, 9, ....... the common difference is
a) 3 b) 5 c) 2 d) 1

2. The common difference of an AP is
a) Always positive b) Always negative
c) Can be positive or negative d) Can be positive, negative or zero

3. What is the formula for common difference of an AP?
a) d = a – a b) d = a – a
n–1 n n n–1
c) d = a – a d) None of these
n –1
4. Which of the following is not an arithmetic progression?
a) 1, 2, 3, 4, 5 b) 5, 8, 11, 14, 17

c) 3, 6, 9, 12, 15 d) 6, 8, 10, 13, 18
5. If 4, x , x , x , 28 are in A.P. the x = ?
1 2 3 3
a) 19 b) 23 c) 22 d) None of these

Answers: 1. c) 2 2. d) Can be positive, negative or zero
3. b) d = a – a 4. d) 6, 8, 10, 13, 18 5. c) 22
n n–1

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