ECAT (Pre-Eng) Mathematics Chapter 8 Sequences and Series

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

An infinite sequence has no

• nth term A
• Last term B
• Sum C
• None of these D

The sum of first 60 natural numbers is

• 1830 A
• 3660 B
• 1640 C
• 1770 D

For an arithmetic series to be convergent it is necessary that the series has

• Finite terms A
• d<0 B
• Infinite terms C
• None of these D

• 12 A
• 13 B
• 14 C
• 15 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

• 
  A
• 
  B
• 
  C
• 
  D

If a^x= b^y= c^zand a, b, c are in G.P. then x, y, z are in

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

A sequence having no last term is called

• arithmetic sequence A
• Geometric sequence B
• Finite sequence C
• Infinite sequence D

Write the first four terms of the arithmetic sequence 5, 2, -1, ... is

• 3 A
• -4 B
• 7 C
• 1 D

Arithmetic mean between x - 3 and x + 5 is

• x + 1 A
• x + 2 B
• x + 3 C
• x + 4 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 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

If a₁, r and a_nare the first term, common ratio and the nth term respectively of a G. P. then a_n=

• a₁rⁿ A
• a₁r^n-1 B
• a₁rⁿ⁺¹ C
• a₁r D

• 
  A
• 
  B
• 
  C
• 
  D

-2, 1, 4, 7,.... is ______

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

Let the sequence 1, 2, 2, 4, 4, 4, 4, 8, 8, 8, 8, 8, 8, 8, 8, ..... where n consecutive terms have the value n, then 1025th term is

• 2⁹ A
• 2¹⁰ B
• 2¹¹ C
• 2⁸ 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

• 0 A
• 1 B
• 2 C
• 3 D

If the domain of sequence is finite set then the sequence is called

• geometric sequence A
• infinite sequence B
• finite sequence C
• arithmetic sequence D

If a, b, c, d, e, f are in A.P.,then e-c is equal to

• 2(c - a) A
• 2(f - d) B
• 2(d - c) C
• d - c D

If all members of a sequence are real numbers then it is called a

• Series A
• Function B
• Real sequence C
• Range D

The third term of a G.P. is 4, The product of first five terms is

• 43 A
• 45 B
• 46 C
• None of these D

The sum of infinite numbers of terms of an arithmetic series is

• Finite A
• Infinite B
• May or may not finite C
• None of these D

The formula an = arn-1represents

• nth term of G.P A
• Sum of the first n terms B
• G.M between a and b C
• None of these D

The nth term of a G.P. is

• a₁rⁿ A
• a₁rⁿ⁺¹ B
• a₁r^n-1 C
• a₁r^-n D

The difference of two consecutive terms of an A.P is called the

• Common difference A
• Common ratio B
• Geometric series C
• Geometric mean D

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

• 
  A
• 
  B
• 
  C
• 
  D

If a₁, r are first term and the common ratio respectively then the sum of an infinite geometric series is

• 
  A
• 
  B
• 
  C
• 
  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