ECAT Pre Engineering MCQ Test With Answer for Chapter 8 Mathematics

Find the sum of the infinite geometric series 2 + 1 + 0.5 + ....

• 3.5 A
• 3 B
• 4 C
• None of these D

If a₁= 3, r = 2, then the nth term of the G.P. is

• 2.3^n-1 A
• 3.2ⁿ B
• 3.2ⁿ⁺¹ C
• 3.2^n-1 D

Every term of a G.P. is positive and also every term is the sum of two preceding terms. Then the common ratio of the G.P. is

• 
  A
• 
  B
• 
  C
• 
  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

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

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

Sequence also called..............

• Series A
• Function B
• progressions C
• Elements D

A Geometric Series is divergent only if

• |r|>1 A
• |r|≥1 B
• |r|=1 C
• None of these D

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

• 1 A
• 2 B
• 3/2 C
• 5/2 D

The sum of an infinite geometric series exist if

• | r | < 1 A
• | r | > 1 B
• r = 1 C
• r = -1 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

• 
  A
• 
  B
• 
  C
• 
  D

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

An A.P., a G.P. and a H.P. have the same first and last terms and the same odd numbers of terms, the middle terms of the three series are in

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

A number H is said to be the H.M. between a and b if a, H, b are in

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

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

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

A sequence having no last term is called

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

The series obtained by adding the terms of a geometric sequence is called

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

If three unequal numbers p, q, r are in H.P. and their squares are in A.P., then the ration p : q : r is

• 
  A
• 
  B
• 
  C
• 
  D

No term of a geometric sequence can be

• 0 A
• 1 B
• 2 C
• 3 D

If a₁= a₂= 2, a_n= a_n-1- 1 (n > 2), then a₅is

• 1 A
• 0 B
• -1 C
• -2 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

The sum of first 60 natural numbers is

• 1830 A
• 3660 B
• 1640 C
• 1770 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

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

• 13 A
• -13 B
• 8 C
• 3 D

• 2 A
• -3/2 B
• 1 C
• 0 D

The formula an = a +(n-1)d for an A.P is called

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