Page 36 - Mathematics Class - X

Viva-Voce

1. Write the formula for the sum of n even natural numbers.
Ans. S = n(n + 1)
n
2. Write the general form of first n even natural numbers.
Ans. The general form of first n even natural numbers is 2n.
3. What are even numbers?

Ans. Numbers which are divisible by 2 are called even numbers.
4. What is d for even natural numbers?

Ans. Common difference (d) = 2 for even natural numbers.
5. In an AP, what is the sum of first n terms?
n
Ans. S = [2a + (n − 1) ] d
n
2

MCQs

1. The sum of first 5 multiples of 2 is
a) 32 b) 30 c) 40 d) 16

2. Which of the following is not an even number?
a) 200 b) 88 c) 101 d) 202 2
2
2
2
3. What is the formula for common difference of an AP?
a) d = a – a b) d = a – a c) d = a – a d) None of these
n–1 n n n–1 n –1
4. For an AP, a – a = 8, then d is equal to
22 18
a) 5 b) 8 c) 2 d) 3

5. The formula for first n even natural numbers is
a) T = a + (n – 1) + d b) T = 2n
n n
c) T = a – (n – 1)d d) None of these
n

Answers: 1. b) 30 2. c) 101 3. b) d = a – a
2
n n–1
4. c) 2 5. b) T = 2n
n

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