ECAT Pre Engineering MCQ Test With Answer for Chapter 8 Mathematics

The element range of sequence are called

• Series A
• progression B
• Members C
• Terms D

If a, b, c are in A.P., then 3^a, 3^b, 3^care in

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

A sequence whose reciprocal is an A.P is called

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

• 
  A
• 
  B
• 
  C
• 
  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

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

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

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

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

• 
  A
• 
  B
• 
  C
• 
  D

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

• 400 A
• 397 B
• 404 C
• 408 D

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

• 8 A
• 4 B
• 4 C
• 16 D

If a, b, c are in AP., a, b, c are in G.P. then A, m²b, c are in

• A.P. A
• G.P. B
• H.P. 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

Arithmetic mean between x - 3 and x + 5 is

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

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

The sum of the squares of three distinct real numbers, which are in G.P., is S². if their sum isαS then

• 
  A
• 
  B
• 
  C
• 
  D

• 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

1 + 2 + 3 + ...... + n = ______

• 
  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

Sum of first n terms of an arithmetic series is

• 
  A
• 
  B
• 
  C
• 
  D

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

• 125 A
• 107 B
• 108 C
• 113 D

The sum of an infinite geometric series exist if

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

The general term of a sequence is denoted by

• a₁ A
• a_n B
• n C
• s_n D

The sum of n terms of a series is denoted by

• d A
• n B
• S_n C
• a_n D

Which one represents a sequence

• an A
• Sn B
• a(n) C
• {an} 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

The common ration of a geometric sequence cannot be

• 0 A
• 1 B
• 2 C
• 3 D