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

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

5th term of a G.P. is 2, then the product of first 9 terms is

• 256 A
• 128 B
• 512 C
• None of these 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

No term of a harmonic sequence can be

• 0 A
• 1 B
• 2 C
• 3 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

The formula an = arn-1represents

• nth term of G.P A
• Sum of the first n terms B
• G.M between a and b C
• None of these D

• 
  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

H.M. between 3 and 7 is

• 
  A
• 
  B
• 
  C
• 
  D

Arithmetic mean between a and b is

• 
  A
• 
  B
• 
  C
• 
  D

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

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

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

• 125 A
• 107 B
• 108 C
• 113 D

A Geometric Series is divergent only if

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

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

• 
  A
• 
  B
• 
  C
• 
  D

A Series which does not coverage to a Unique sum is called

• Harmonic Series A
• Oscillatroy Series B
• Arithmetic Series C
• None of these D

The common ration of a geometric sequence cannot be

• 0 A
• 1 B
• 2 C
• 3 D

• 12 A
• 13 B
• 14 C
• 15 D

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

• 
  A
• 
  B
• 
  C
• 
  D

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

• 54 A
• 12 B
• 4 C
• 9 D

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

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

an -an-1,∀n∈N∧n>1 in an A.P is called

• Common difference A
• nth term B
• Common ratio C
• None of these D

The third term of the sequence a_n= (-1)^n-1(n-7) is ______

• 8 A
• 4 B
• -4 C
• 8 D

No term of a geometric sequence can be

• 0 A
• 1 B
• 2 C
• 3 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 formula an = a +(n-1)d for an A.P is called

• nth term of an A.P A
• Sum of first n terms B
• A,M between a and b C
• None of the above D

If G is a G.M between a and b then a,G,b are in

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

The general term of a sequence is denoted by

• a₁ A
• a_n B
• n C
• s_n D