These Sequences And Series Class 11 MCQ and Answers are most important for your upcoming examinations including JEE Main & JEE Advanced. These Sequences And Series Class 11 MCQ and Answers will help you to score good marks in your exams by helping you to prepare the concepts better and hence, help you to understand the concepts more clearly.

## Sequences And Series Class 11 MCQ and Answers

1. The lengths of three unequal edges of a rectangular solid block are in G.P. If the volume of the block is 216 cm^{3} and the total surface area is 252 cm^{2}, then the length of the longest edge is

(A) 12 cm

(B) 6 cm

(C) 18 cm

(D) 3 cm

**Answer:** 12 cm

2. If the sum of the first 2n terms of the A.P. 2, 5, 8, ….., is equal to the sum of the first n terms of the A.P. 57, 59, 61, ….., then n equals

(A) 49^{2} – 1

(B) 49^{2}

(C) 50^{2}+l

(D) 49^{2} +2

**Answer:** 49^{2} +2

3. The minimum value of 4^{x}+4^{1-x}, x€ R is

(A) 2

(B) 4

(C) 1

(D) 0

**Answer:** 4

4. The first term of a GP is 1. The sum of the third term and fifth term is 90. The common ratio of GP is

(A) 1

(B) 2

(C) 3

(D) 4

**Answer:** 3

5. If the sum of the first 2n terms of the A.P. 2, 5, 8, ….., is equal to the sum of the first n terms of the A.P. 57, 59, 61, ….., then n equals

(A) 10

(B) 12

(C) 11

(D) 13

**Answer:** 11

6. If the sum of the roots of the quadratic equation ax² + bx + c = 0 is equal to the sum of the squares of their reciprocals, then a/c, b/a, c/b are in

(A) A.P.

(B) G.P.

(C) H.P.

(D) A.G.P.

**Answer:** H.P.

7. If 1/(b + c), 1/(c + a), 1/(a + b) are in AP then

(A) a, b, c are in AP

(B) a², b², c² are in AP

(C) 1/1, 1/b, 1/c are in AP

(D) None of these

**Answer:** a², b², c² are in AP

8. The 35th partial sum of the arithmetic sequence with terms an = n/2 + 1

(A) 240

(B) 280

(C) 330

(D) 350

**Answer:** 350

9. The sum of series 1/2! + 1/4! + 1/6! + ….. is

(A) e² – 1 / 2

(B) (e – 1)² /2 e

(C) e² – 1 / 2 e

(D) e² – 2 / e

**Answer:** (e – 1)² /2 e

10. If a, b, c are in G.P., then the equations ax² + 2bx + c = 0 and dx² + 2ex + f = 0 have a common root if d/a, e/b, f/c are in

(A) AP

(B) GP

(C) HP

(D) none of these

**Answer:** AP

11. The sum of n terms of the series (1/1.2) + (1/2.3) + (1/3.4) + …… is

(A) n/(n+1)

(B) 1/(n+1)

(C) 1/n

(D) None of these

**Answer:** n/(n+1)

12. The sum of two numbers is 13/6 An even number of arithmetic means are being inserted between them and their sum exceeds their number by 1. Then the number of means inserted is

(A) 2

(B) 4

(C) 6

(D) 8

**Answer:** 6

13. a, b, c Î R+ and from an A.P. if abc = 4, then the minimum value of b is

(A) (2)^{2/3}

(B) (2)^{1/3}

(C) (4)^{2/3}

(D) None of these

**Answer:** (2)^{2/3}

14. If 2/3, k, 5/8 are in AP then the value of k is

(A) 31/24

(B) 31/48

(C) 24/31

(D) 48/31

**Answer:** 31/48

15. Three numbers form an increasing GP. If the middle term is doubled, then the new numbers are in Ap. The common ratio of GP is

(A) 2 + ?3

(B) 2 – ?3

(C) 2 ± ?3

(D) None of these

**Answer:** 2 + ?3

16. The sum of two numbers is 13/6 An even number of arithmetic means are being inserted between them and their sum exceeds their number by 1. Then the number of means inserted is

(A) 2

(B) 4

(C) 6

(D) 8

**Answer:** 6

17. If a, b, c are in AP then

(A) b = a + c

(B) 2b = a + c

(C) b² = a + c

(D) 2b² = a + c

**Answer:** 2b = a + c

18. If the third term of an A.P. is 7 and its 7 th term is 2 more than three times of its third term, then the sum of its first 20 terms is

(A) 228

(B) 74

(C) 740

(D) 1090

19. The numbers 1, 4, 16 can be three terms (not necessarily consecutive) of

(A) No A.P.

(B) Only 1 or 2 G.Ps

(C) Infinite number of A.Ps

(D) Infinite number of G.Ps

**Answer:** Infinite number of A.Ps

20. 2¹ + 2² +2³ +….+2 =

(A) 2(2^{n} – 1) 2

(B) 2(2^{n-1} -1) 3

(C) 2(2^{n+1} -1)

(D) None of Above

**Answer:** 2(2^{n} – 1) 2