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

The general term of the A.P. is

• a₁+ (n - 1) d A
• n + (a₁- 1) d B
• d + (n - 1) a₁ C
• None of these D

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

Find the next two terms of 7, 9, 12, 16,...

• 18, 20 A
• 19, 22 B
• 20, 25 C
• 21, 27 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

The 10th common term between the series 3+7+11+....... and 1 + 6 +11 + ....... is

• 191 A
• 193 B
• 211 C
• None of these D

For three consecutive terms in A.P middle term is called

• A.M A
• nth term B
• Central term C
• None of these D

If b₁, b₂, b₃, ... are in G.P. with first term unity and common ratio r, then the minimum value of b₁- b₃+ b₅is equal to

• 3/4 A
• 1/4 B
• 1 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 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

• 15/23 A
• 7/15 B
• 7/8 C
• 15/7 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

• 
  A
• 
  B
• 
  C
• 
  D

H.M. between 3 and 7 is

• 
  A
• 
  B
• 
  C
• 
  D

For an A.P common difference d

• Can be zero A
• May or may not zero B
• Cannot be zero C
• None of these D

Which one represents a sequence

• an A
• Sn B
• a(n) C
• {an} D

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

• 400 A
• 397 B
• 404 C
• 408 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

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 a₁= a₂= 2, a_n= a_n-1- 1 (n > 2), then a₅is

• 1 A
• 0 B
• -1 C
• -2 D

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

• -82 A
• 82 B
• 85 C
• -85 D

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

• 13 A
• -13 B
• 8 C
• 3 D

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

• 8 A
• 4 B
• 4 C
• 16 D

The difference of two consecutive terms of an A.P. is called ______

• General term A
• Common ratio B
• Common difference 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

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

• 
  A
• 
  B
• 
  C
• 
  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

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

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