ECAT Pre Engineering MCQ Test With Answer for Chapter 8 Mathematics

• A.P. A
• G.P. B
• H.P. 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

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

• 1/2 A
• 2 B
• 1/4 C
• 4 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

Let a₁, a₂, a₃, a₄and a₅be such that a₁, a₂, and a₃are in A.P., a₂, a₃and a₄are in G.P and a₃, a₄and a₅are in H.P. Then, a₁, a₃and a₅are in

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

Geometric mean between a and b is

• 
  A
• 
  B
• 
  C
• 
  D

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

• 
  A
• 
  B
• 
  C
• 
  D

1,1/3,1/5,1/7,1/9..... is a

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

Write the first four terms of the arithmetic sequence 5, 2, -1, ... is

• 3 A
• -4 B
• 7 C
• 1 D

• 
  A
• 
  B
• 
  C
• 
  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 Sn is a definite number as n → ∞,then the geometric series is

• Convergent A
• Divergent B
• Oscillatroy C
• None of these D

A,G,H are in

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

If the pth, qth, and rth terms of an A.P. are in G.P:., then the common ratio of the G.P. is

• 
  A
• 
  B
• 
  C
• 
  D

What is the 26th term of the sequence, if its general term is a_{n = (-1)}ⁿ⁺¹

• 2 A
• 26 B
• 27 C
• 1 D

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

• 
  A
• 
  B
• 
  C
• 
  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 harmonic mean between a and b 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 nth term of an A.P is (3n+5) Its 75th term is

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

If 5,7 and 9 are A.Ms between a and b, then a and b is equal to

• 2 and 12 A
• 1 and 10 B
• 3 and 11 C
• -7 and 2 D

The sum of an indicated number of terms in a sequence is called

• sequence A
• progression B
• Series C
• Mean D

The sixth term of the sequence 1,3,12,60....is

• 1500 A
• 72 B
• 2160 C
• 2520 D

The third term of a G.P. is the square of first term. If the second term is 8, then the 6th term is

• 120 A
• 124 B
• 128 C
• 132 D

H.M. between 3 and 7 is

• 
  A
• 
  B
• 
  C
• 
  D

• 2 A
• -3/2 B
• 1 C
• 0 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