CBSE  /  Class 11  /  Maths  /  Sequences and Series

  • 1. 
    If 1/(b + c), 1/(c + a), 1/(a + b) are in AP then

  • a, b, c are in AP
  • a², b², c² are in AP
  • 1/1, 1/b, 1/c are in AP
  • None of these

  • 2. 
    The 35th partial sum of the arithmetic sequence with terms an = n/2 + 1

  • 240
  • 280
  • 330
  • 350

  • 3. 
    The sum of two numbers is 13/6 An even number of arithmetic means are being inserted between them and their sum exceeds their number by 1. Then the number of means inserted is

  • 2
  • 4
  • 6
  • 8

  • 4. 
    The first term of a GP is 1. The sum of the third term and fifth term is 90. The common ratio of GP is

  • 1
  • 2
  • 3
  • 4

  • 5. 
    The sum of AP 2, 5, 8, .....up to 50 terms is

  • 3557
  • 3775
  • 3757
  • 3575

  • 6. 
    If 2/3, k, 5/8 are in AP then the value of k is

  • 31/24
  • 31/48
  • 24/31
  • 48/31

  • 7. 
    The sum of n terms of the series (1/1.2) + (1/2.3) + (1/3.4) + ...... is

  • n/(n+1)
  • 1/(n+1)
  • 1/n
  • None of these

  • 8. 
    If the third term of an A.P. is 7 and its 7 th term is 2 more than three times of its third term, then the sum of its first 20 terms is

  • 228
  • 74
  • 740
  • 1090

  • 9. 
    If the sum of the first 2n terms of the A.P. 2, 5, 8, ....., is equal to the sum of the first n terms of the A.P. 57, 59, 61, ....., then n equals

  • 10
  • 12
  • 11
  • 13

  • 10. 
    If a is the A.M. of b and c and G1 and G2 are two GM between them then the sum of their cubes is

  • abc
  • 2abc
  • 3abc
  • 4abc
Report Question
warning
Practice More On Sequences and Series
Quiz 1 Quiz 2
access_time
  Time