ECAT Pre Engineering Mathematic MCQ Test With Answer for Chapter 8 (Sequences and Series)

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  A
• 
  B
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  C
• 
  D

The 31 term of the A.P 5,2,-1.....is

• -82 A
• 82 B
• 85 C
• -85 D

If x,y are two positive distinct numbers then

• A>G>H A
• A<G<H B
• A=G=H C
• None of these D

The A.M. of two numbers is 34 and G.M. is 16, the numbers are

• 2 and 64 A
• 64 and 3 B
• 64 and 4 C
• None of these D

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  A
• 
  B
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  C
• 
  D

If x, y, z are the pth, qth, rth terms of an A.P. and also of G.P., then x^y-z. y^z-x. z^x-yeqals

• xyz A
• 0 B
• 1 C
• None of these D

• 1 A
• 2 B
• 3/2 C
• 5/2 D

The fifth term of the sequence a_n= 2n + 3 is ______

• 13 A
• -13 B
• 8 C
• 3 D

If a, b, c are in A.P., then 3^a, 3^b, 3^care in

• A.P. A
• G.P. B
• H.P. C
• None of these D

An infinite arithmetic series is always

• Convergent A
• Oscillatory B
• Divergent C
• None of these D

if a_{9 =19,a9=31 are the 6th and 9th term of an A.P. and d=4 is the common difference, then 18th term of the sequence is}

• 65 A
• 67 B
• 71 C
• 75 D

If a_n= 2n -3, write the first four terms

• -3, -1, 1, 3 A
• 1, 3, 5, 7 B
• -1, 1, 3, 5 C
• None of these D

5th term of a G.P. is 2, then the product of first 9 terms is

• 256 A
• 128 B
• 512 C
• None of these D

Sum of n terms of a geometric series if | r | < 1 is

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  A
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  B
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  C
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  D

The harmonic mean between a and b is

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  A
• 
  B
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  C
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  D

What is the 26th term of the sequence, if its general term is a_{n = (-1)}ⁿ⁺¹

• 2 A
• 26 B
• 27 C
• 1 D

The sum of n terms of a series is denoted by

• d A
• n B
• S_n C
• a_n D

A Series which does not coverage to a Unique sum is called

• Harmonic Series A
• Oscillatroy Series B
• Arithmetic Series C
• None of these D

The next term of the sequence 1, 2, 4, 7, 11, ..... is.

• 15 A
• 16 B
• 17 C
• 18 D

The number of divisors of 1029, 1547 and 122 are in

• A.P. A
• G.P. B
• H.P. C
• None of these D

• 1, 1/2, 0 A
• 1, 2, 1 B
• 1, 2, 3 C
• 1, 2, 0 D

The element range of sequence are called

• Series A
• progression B
• Members C
• Terms D

Given two numbers a and b. Let A denote the single A.M. between these and S denote the sum of n A.M.'s between them. Then S/A depends upon

• n, a, b A
• n, a B
• n, b C
• n D

The sides of a right angled triangle are in A.P The ratio of sides is

• 1:2:3 A
• 3:4:5 B
• 2:3:4 C
• 5:8:3 D

If x,y are two -ve distinct numbers then

• A>G>H A
• A<G<H B
• A=G=H C
• None of these D

1/2,1/3,1/4,1/5.........is

• a geometric sec A
• an arithmetric series B
• finite sequence C
• an infinite sequece D

• 15/23 A
• 7/15 B
• 7/8 C
• 15/7 D

The third term of a G.P. is the square of first term. If the second term is 8, then the 6th term is

• 120 A
• 124 B
• 128 C
• 132 D

The series obtained by adding the terms of an arithmetic sequence is called the

• Infinite series A
• Harmonic series B
• Geometric series C
• Arithmetic series D

Three consecutive terms of a progression are 30, 24, 20. The next terms of the progression is

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  A
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  B
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  C
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  D