# Series and Parallel Sequences MCQs

## Series and Parallel Sequences MCQs

1: G1,G2,…,Gn are said to be n geometric means between a and b if a,G1,…Gn,b is called ______________. Select the correct option.
A. A.P
B. a sequence
C. not a sequence
D. G.P
E. All of these
F. Both A and B

D

2. If H,G,A are arithmetic, geometric and harmonic means between b and a respectively, then H,G,Aare______________. Select the correct option.

A. Real numbers
B. in G.P
C. in A.P
D. in H.P
E. All of these
F. Both A and B

B

3: Common difference of sequence 5,8,11,14,… is called ______________. Select the correct option.

A. 3
B. −3
C. 0
D. 1
E. All of these
F. Both A and B

C

4: Arithmetic mean between 2+√(2) and 2-√(2) is called ______________. Select the correct option.

A. 4
B. 2
C. √(2)
D. 0
E. All of these
F. Both A and B

B

5: 2¹ + 2² +2³ +….+2n =______________. Select the correct option.
A. 2(2n+1 -1)
B. 2(2n – 1)
C. 2(2n-1 -1)
D. None of Above
E. All of these
F. Both A and B
B

6: Fifth term of sequence an = 2n+3 is called _______________. Select the suitable option.
A. 13
B. −13
C. −7
D. 7
E. All of these
F. Both A and B
A

7: 5th term of G.P 3,6,12,… is called _______________. Select the suitable option.

A. 3
B. 15
C. 48
D. 2
E. All of these
F. Both A and B

C

8: A.M between 3√(5) and 5√(5) is called _______________. Select the suitable option.

A. 4√(5)
B. √(5)
C. 2√(5)
D. 3√(5)
E. All of these
F. Both A and B

A

9: A.M between 1-x+x² and 1+x+x² is called _______________. Select the suitable option.

A. 1+x²
B. 2-x²
C. 2+ x²
D. 1-x²
E. All of these
F. Both A and B

A

10: Series obtained by adding term of arithmetic sequences is called _______________. Select the suitable option.

A. infinite series
B. harmonic series
C. geometric series
D. arithmetic series
E. All of these
F. Both A and B

D

11: Sum of series 1+1/3+1/3² +… is _____________.which of the following is a suitable option.

A. 10⁄9
B. 2
C. ³⁄2
D. 4⁄3
E. All of these
F. Both A and B

C

12: If A and H are arithmetic and harmonic mean between 2 and 3, then A + H = _____________.which of the following is a suitable option.

A. 32/4
B. 49/20
C. 49/10
D. 49/5
E. All of these
F. Both A and B

C

13: A.M between 9 and 11 is _____________.which of the following is a suitable option.

A. 0
B. 10
C. 9
D. 5
E. All of these
F. Both A and B

B

14: Sum of first 15th terms of series 3+19+35+… is _____________.which of the following is a suitable option.

A. 23
B. 1725
C. 345
D. 69
E. All of these
F. Both A and B

B

15: 2,4,6,8,10,12,… is called _____________.which of the following is a suitable option.
A. arithmetic series
B. G.P
C. A.P
D. Geometric series
E. All of these
F. Both A and B

C

16: No terms of a Harmonic sequence can be ____________.Choose the correct option.

A. 0
B. 1
C. 2
D. 3
E. All of these
F. Both A and B

A

17: If n is the total number of harmonic mean between x and then mth harmonic mean between x and y is ____________.Choose the correct option.

A. (n+1)ba
B. (n+1)ab/(n+1)+n(a-b)
C. (n+1)ab/(n+1)b+m(a-b)
D. (n+1)b+m(a-b)
E. All of these
F. Both A and B

C

18: 2nd term of sequence with general term n² – 4/2 is ____________.Choose the correct option.

A. 0
B. 3
C. −3
D. 1
E. All of these
F. Both A and B

A

19: Sum of 1st 6 terms of series 1+7+13+… is ____________.Choose the correct option.

A. 96
B. 12
C. 24
D. 48
E. All of these
F. Both A and B

A

20: H1,H2,…,Hn are said to be n harmonic means between x and y if x,H1,H2…,Hn,y form ____________.Choose the correct option.
A. Harmonic series
B. H.P
C. A.P
D. G.P
E. All of these
F. Both A and B

B

21: If a and d are first term and common difference of A.P respectively, then nth term of corresponding H.P is _____________. Select the correct option.
A. an = a/a+(n-1)d
B. an = a+(n-1)d
C. an = 1/a+(n-1)d
D. an = a/1+(n-1)d
E. All of these
F. Both A and B

C

22: If n is the total number of G.M between a and b than nth geometric mean between a and b is _____________. Select the correct option.
A. ab
B. a(b/a)n/n+1
C. a(b/a)m/n+1
D. b(a/b)m/n+1
E. All of these
F. Both A and B

C

23:Common ratio r is _____________. Select the correct option.
A. r ≤ −1,r≥ 1
B. −1 < r < 1
C. −1 ≤ r ≤ 1
D. r < −1,r > 1
E. All of these
F. Both A and B

B

24: Sum of series 1+1/2+1/2² + … is _____________. Select the correct option.
A. 10⁄9
B. 2
C. ³⁄2
D. 4⁄3
E. All of these
F. Both A and B

B

25: 1,8,15,22,29,36,… is _____________. Select the correct option.
A. arithmetic series
B. G.P
C. A.P
D. Geometric series
E. All of these
F. Both A and B

C

26: A.P whose nth term is 2n-1 is _____________. Which of the following is a correct option?

A. 5,3,1,…
B. 1,3,6,…
C. 2,3,5,…
D. 1,3,5,…
E. All of these
F. Both A and B

D

27: Arithmetic mean between a and b is _____________. Which of the following is a correct option?

A. ±√(ab)
B. a-b/2
C. b-a/2
D. a + b/2
E. All of these
F. Both A and B

C

28: If an+2 + bn+2/an+1 + bn+1 is geometric mean between a and b, then n = _____________. Which of the following is a correct option?

A. −0.5
B. −1
C. 1
D. −2
E. All of these
F. Both A and B

D

29: A number G is said to be geometric mean between 2 numbers a and b if a,G,b is_____________. Which of the following is the correct option?

A. G.P
B. a sequence
C. A.P
D. not a sequence
E. All of these
F. Both A and B

D

30: Geometric mean between -2ι and 8ι are _____________. Which of the following is a correct option?
A. ±1
B. ±4
C. ±3
D. ±2
E. All of these
F. Both A and B

B

31: A.M between x-3 and x+5 is called _______________. Select the correct option.

A. 2x+2
B. x-1
C. x+1
D. 2x-1
E. All of these
F. Both A and B

C

32: Harmonic mean between two numbers a and b is _______________. Select the correct option.

A. 2ab/a-b
B. a+b/2ab
C. a-b/2ab
D. 2ab/(a+b)
E. All of these
F. Both A and B

D

33: Series obtained by adding terms of geometric sequences is called _______________. Select the correct option.

A. infinite series
B. harmonic series
C. geometric series
D. arithmetic series
E. All of these
F. Both A and B

B

34: If H is harmonic mean between 7 and 8, then H/2 = _______________. Select the correct option.

A. 14/15
B. 112/15
C. 56/15
D. 28/15
E. All of these
F. Both A and B

C

35: 1/2,1/7,1/12,… is _______________. Select the correct option.
A. a harmonic series
B. an arithmetic progression
C. a Geometric Progression (GP)
D. a harmonic progression
E. All of these
F. Both A and B
D

36: If an+1 + bn+1/an + bn is harmonic mean between a and b, then n = ________________. Select the suitable option.

A. 0
B. −1
C. 1
D. −2
E. All of these
F. Both A and B

37: A geometric mean between 2 and 4 is ________________. Select the suitable option.

A. ±√(2)
B. ±8√(2)
C. ±4√(2)
D. ±2√(2)
E. All of these
F. Both A and B

D

38: Twice sum of 1st fifteen terms of series 5+10+20+ … is ________________. Select the suitable option.

A. 10230
B. 341
C. 1023
D. 5115
E. All of these
F. Both A and B

A

39: 5th term of and nth term of A.P 1,5,… are ________________. Select the suitable option.

A. 17,4n
B. 17,4n-3
C. 4n-3,17
D. 17,3n-4
E. All of these
F. Both A and B

B

40: 2 geometric means between a and b are ________________. Select the suitable option.
A. ab
B. a(b/a)1/2,b
C. a(a/b)1/2,b
D. a(b/a)1/2,b
E. All of these
F. Both A and B 