ECAT Pre Engineering MCQ Test With Answer for Chapter 8 Mathematics

The sum of indicated terms of a sequence is called

• Arithmetic series A
• Series B
• Harmonic series C
• None of these 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

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

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

A Geometric Series is divergent only if

• |r|>1 A
• |r|≥1 B
• |r|=1 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

In following question, a number series is given with one term missing. choose the correct alternative that will same pattern and fill in the blank spaces.1 , 4, 9, 16, 25, x

• 35 A
• 36 B
• 48 C
• 49 D

If all members of a sequence are real numbers then it is called

• A.P A
• Real Sequence B
• G.P 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

A number A is called the arithmetic mean between a and b if a, A, b is ______

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

If all members of a sequence are real numbers then it is called a

• Series A
• Function B
• Real sequence C
• Range D

The sum of an infinite geometric series exist if

• | r | < 1 A
• | r | > 1 B
• r = 1 C
• r = -1 D

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

• -82 A
• 82 B
• 85 C
• -85 D

If a,b,c are in arithmetic progression, then 1/a,1/b.1/c are in

• A.M A
• G.M B
• H.M C
• G.P 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 sum of an indicated number of terms in a sequence is called

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

If S_rdenotes the sum of the first r terms of a G.P., then S_n, S_2n- S_n, S_3n- S_2nare in

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

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

• 
  A
• 
  B
• 
  C
• 
  D

The sum of first 60 natural numbers is

• 1830 A
• 3660 B
• 1640 C
• 1770 D

Find the geometric mean between 4 and 16

• 
  A
• 
  B
• 
  C
• 
  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

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

• 0 A
• 1 B
• 2 C
• 3 D

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

• 54 A
• 12 B
• 4 C
• 9 D

If A, G, H are the arithmetic, geometric and harmonic means between a and b respectively then A, G, H are in

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

• 12 A
• 13 B
• 14 C
• 15 D

• 1 A
• 2 B
• 3/2 C
• 5/2 D

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

• 8 A
• 4 B
• -4 C
• 8 D