ECAT Pre General Science MCQ Test With Answer for Mathematics Chapter 8

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

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

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 sequence of number whose reciprocals form an arithmetic sequence is called

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

An infinite arithmetic series is always

• Convergent A
• Oscillatory B
• Divergent C
• None of these 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

How many term are there in the A.P, in which a₁ = 11 , a_n =68, d=3

• 30 A
• 27 B
• 20 C
• 21 D

Which term of the A.P 5,8,11,24.............is 320

• 104th A
• 106th B
• 105th C
• 64th D

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

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

• 1 A
• 0 B
• -1 C
• -2 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

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

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

• 15/23 A
• 7/15 B
• 7/8 C
• 15/7 D

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

• -82 A
• 82 B
• 85 C
• -85 D

If x,y are two positive distinct numbers then

• A>G>H A
• A<G<H B
• A=G=H C
• None of these D

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

• 
  A
• 
  B
• 
  C
• 
  D

The fifth term of an A.P. Whose first term is 5 and common difference is 3,is

• 20 A
• 17 B
• 25 C
• 30 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

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

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

If x, y, z are the pth, qth, rth terms of an A.P. and also of G.P., then x^y-z. y^z-x. z^x-yeqals

• xyz A
• 0 B
• 1 C
• None of these D

The next term of the sequence 1, 2, 4, 7, 11, ..... is.

• 15 A
• 16 B
• 17 C
• 18 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

An infinite sequence has no

• nth term A
• Last term B
• Sum 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 third term of the sequence a_n= (-1)^n-1(n-7) is ______

• 8 A
• 4 B
• -4 C
• 8 D

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

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

The 26th term of the A.P -2,-4,10,.............is

• 136 A
• -136 B
• 148 C
• -148 D

Every term of a G.P. is positive and also every term is the sum of two preceding terms. Then the common ratio of the G.P. is

• 
  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