ECAT Pre Engineering MCQ Test With Answer for Chapter 8 Mathematics

A sequence is a functions whose domain is a subset of the set of

• Natural numbers A
• Real numbers B
• Whole numbers C
• Rational numbers D

No term of a geometric sequence can be

• 0 A
• 1 B
• 2 C
• 3 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

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

Find the geometric mean between 4 and 16

• 
  A
• 
  B
• 
  C
• 
  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 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

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

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

The 6th term of the sequence 7,9,12,16......is

• 27 A
• 32 B
• 20 C
• 19 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
• 
  B
• 
  C
• 
  D

Sum of first n terms of an arithmetic series is

• 
  A
• 
  B
• 
  C
• 
  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

An indicated sum of terms of a sequence is represented by

• Sn A
• an B
• S(n) C
• {Sn} D

The element range of sequence are called

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

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

• 
  A
• 
  B
• 
  C
• 
  D

If the domain of sequence is finite set then the sequence is called

• geometric sequence A
• infinite sequence B
• finite sequence C
• arithmetic sequence D

• 
  A
• 
  B
• 
  C
• 
  D

If a₁and r are the first term and the common ratio respectively then (n + 1)th term of the G.P. is

• 0 A
• a₁r^n-1 B
• a₁rⁿ⁺¹ C
• a₁rⁿ D

Write the first four terms of the sequence if a_n= (-1)ⁿn²

• -1, 4, -9, 16 A
• 1, -4, 9, 16 B
• 1, 4, 9, 16 C
• None of these 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 31 term of the A.P 5,2,-1.....is

• -82 A
• 82 B
• 85 C
• -85 D

If a_n= 2n -3, write the first four terms

• -3, -1, 1, 3 A
• 1, 3, 5, 7 B
• -1, 1, 3, 5 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

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

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

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

if a_{9 =19,a9=31 are the 6th and 9th term of an A.P. and d=4 is the common difference, then 18th term of the sequence is}

• 65 A
• 67 B
• 71 C
• 75 D

Sum of n terms of a geometric series if | r | < 1 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