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

An A.P. consists of n(odd terms) and its middle term is m. then the sum of the A.P. is

• 2 mn A
• 1/2 mn B
• mn C
• mn² 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

In following question, a number series is given with one term missing. choose the correct alternative that will same pattern and fill in the blank spaces.1 , 4, 9, 16, 25, x

• 35 A
• 36 B
• 48 C
• 49 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

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

• Series A
• Function B
• progressions C
• Elements 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

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

• 125 A
• 107 B
• 108 C
• 113 D

The common ration of a geometric sequence cannot be

• 0 A
• 1 B
• 2 C
• 3 D

3, 6, 12,.... is

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

• 
  A
• 
  B
• 
  C
• 
  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

An indicated sum of terms of a sequence is represented by

• Sn A
• an B
• S(n) C
• {Sn} D

A number A is called the arithmetic mean between a and b if a, A, b is ______

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

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

• 1500 A
• 72 B
• 2160 C
• 2520 D

p, q, r and s are integers. If the A.M. of the roots of x2- px + q2= 0 and G.M. of the roots of x2- rx + s2= 0 are equal, then

• q is an odd integer A
• r is an even integer B
• p is an even integer C
• s is an odd integer 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

Let S_ndenote the sum of the first n terms of an A.P. If S_2n= 3 S_n: S_nis equal to

• 4 A
• 6 B
• 8 C
• 10 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

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

The nth term of an A.P is (3n+5) Its 75th term is

• 26 A
• 7 B
• 21 C
• Cannot be determined D

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

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

A Geometric Series is divergent only if

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

The general term of a sequence is denoted by

• a₁ A
• a_n B
• n C
• s_n D

an -an-1,∀n∈N∧n>1 in an A.P is called

• Common difference A
• nth term B
• Common ratio C
• None of these D

A function whose domain is a subset of natural numbers is called ______

• Identity function A
• Sequence B
• Onto function C
• Series 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

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

• A.P A
• Real Sequence B
• G.P C
• None of these D

Which term of the A.P 5,8,11,24.............is 320

• 104th A
• 106th B
• 105th C
• 64th D

An infinite sequence has no

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