ECAT Pre Engineering MCQ Test With Answer for Chapter 8 Mathematics

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

An indicated sum of terms of a sequence is represented by

• Sn A
• an B
• S(n) C
• {Sn} 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

Three consecutive terms of a progression are 30, 24, 20. The next terms of the progression is

• 
  A
• 
  B
• 
  C
• 
  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

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

• 13 A
• -13 B
• 8 C
• 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

If a,b,c are in arithmetic progression, then 1/a,1/b.1/c are in

• A.M A
• G.M B
• H.M C
• G.P D

The nth term of an A.P., is 12-4n. Its common difference is

• 8 A
• 4 B
• 4 C
• 16 D

• 1 A
• 2 B
• 3/2 C
• 5/2 D

Geometric mean between a and b is

• 
  A
• 
  B
• 
  C
• 
  D

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

• A.M A
• A.P B
• G.P C
• G.M D

• 
  A
• 
  B
• 
  C
• 
  D

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

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

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

In an A.P,a +(n-a)d is

• 1st term A
• General term B
• Last term C
• None of these D

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

• 24 A
• 31 B
• 26 C
• 23 D

• 
  A
• 
  B
• 
  C
• 
  D

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

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

If #n = (n-5)2 + 5, then find #3 x #4.

• 54 A
• 12 B
• 4 C
• 9 D

• 
  A
• 
  B
• 
  C
• 
  D

The sum of an infinite geometric series exist if

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

The numbers of G₁, G₂, G₃...... G_nare called n geometric means between a and b is a, G₁, G_2,G₃, ... G_n, b are in

• H.P. A
• A.P. B
• G.P. C
• None of these 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 first 60 natural numbers is

• 1830 A
• 3660 B
• 1640 C
• 1770 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

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

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

• 12 A
• 13 B
• 14 C
• 15 D

Arithmetic mean between x - 3 and x + 5 is

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