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

Arithmetic mean between a and b is

• 
  A
• 
  B
• 
  C
• 
  D

The 7th term of the A.P 7,11,15,is

• 24 A
• 31 B
• 26 C
• 23 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

No term of a harmonic sequence can be

• 0 A
• 1 B
• 2 C
• 3 D

an - an-1 will be common difference in an A.P if

• n = 1∀n∈ N A
• n>1∧n∈N B
• n∈Z C
• None of the above D

Arithmetic mean between x - 3 and x + 5 is

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

• 1/2 A
• 2 B
• 1/4 C
• 4 D

The n numbers A₁,A₂,A₃,.....A_nare called an arithmetic means between a and b if a.A₁,A₂,A₃.....A_n, b is ______

• An arithmetic series A
• An arithmetic sequence B
• A geometric sequence C
• A harmonic sequence 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

• 2²- n - 1 A
• 1 - 2^-n B
• n + 2^-n-1 C
• 2ⁿ- 1 D

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

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

Sum of first n terms of an arithmetic series is

• 
  A
• 
  B
• 
  C
• 
  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

If S_rdenotes the sum of the first r terms of a G.P., then S_n, S_2n- S_n, S_3n- S_2nare in

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

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

• -82 A
• 82 B
• 85 C
• -85 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

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

The sum of first twenty odd integers in A.P is

• 400 A
• 397 B
• 404 C
• 408 D

• 
  A
• 
  B
• 
  C
• 
  D

The 26th term of the A.P -2,-4,10,.............is

• 136 A
• -136 B
• 148 C
• -148 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

How many term are there in the A.P, in which a₁ = 11 , a_n =68, d=3

• 30 A
• 27 B
• 20 C
• 21 D

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

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

• 3 A
• -4 B
• 7 C
• 1 D

If the pth, qth, and rth terms of an A.P. are in G.P:., then the common ratio of the G.P. is

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

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

3, 6, 12,.... is

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

A Geometric Series is divergent only if

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