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

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

H₁, H₂, H₃, .... H_nare called n harmonic means between a and b if a, H₁, H₂, H₃, ... H_nb are in

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

The sum of n terms of a series is denoted by

• d A
• n B
• S_n C
• a_n D

The sixth term of the sequence 1,3,12,60....is

• 1500 A
• 72 B
• 2160 C
• 2520 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 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

• 15/23 A
• 7/15 B
• 7/8 C
• 15/7 D

The 6th term of an arithmetic sequence whose first term is 3 and common difference in zero is

• 18 A
• 6 B
• 3 C
• 0 D

The seventh term of an A.P whose first term is P and common difference is q. is

• P-6q A
• P+6q B
• P-4q C
• P-nq D

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

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

99th term of the series 2 + 7 + 14 + 23 + 34 + ..... is

• 9998 A
• 9999 B
• 10000 C
• None of these D

The sum of indicated terms of a sequence is called

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

If p, q, r and in A.P., a is G.M. between p and q and b is G.M. between q and r, then a², q², b²are in

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

• 
  A
• 
  B
• 
  C
• 
  D

The sum of all 2 digit number is

• 4750 A
• 3776 B
• 4895 C
• 4905 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

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

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

A series consisting of an unlimited number of terms is termed as an

• Finite sequence A
• Infinite sequence B
• ^{Infinite series} C
• geometric sequence D

If P, Q, R be the A.M., G.M., H.M. respectively between any two rational numbers a and b, then P - Q 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

• 
  A
• 
  B
• 
  C
• 
  D

H.M. between 3 and 7 is

• 
  A
• 
  B
• 
  C
• 
  D

The sum of an indicated number of terms in a sequence is called

• sequence A
• progression B
• Series C
• Mean D

How many numbers are there between 103 and 750 which are divisible by 6

• 125 A
• 107 B
• 108 C
• 113 D

An infinite sequence has no

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

pth term of an H.P. is qr and qth term is pr then the rth term of the H.P. is

• pqr A
• 1 B
• pq C
• pqr² D

• 
  A
• 
  B
• 
  C
• 
  D

If A, G, H are the arithmetic, geometric and harmonic means between a and b respectively then A, G, H are in

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

If 6th term of a series in A.P, is -2 and 8th term is -8, the first term of the serie is

• 13 A
• -13 B
• 18 C
• -10 D

If A is such that a,A,B are in A.P then A is called

• A.M A
• Common ratio B
• Common difference C
• None of these D