Number Series


Direction: In each of the following questions a number series is given. A number is given after the series and then (a), (b), (c), (d) and (e) are given. According to the given series, you have to form a new series which begins with the given number, and then answer the question asked.

  1. 2514665114
    39(a)(b)(c)(d)(e)
    Which of the following numbers will come in place of (e) ?
    1. 122
    2. 119
    3. 112
    4. 94
    5. None of these

  1. View Hint View Answer Discuss in Forum

    The given series is in the below pattern ,
    First series :-
    First term = 25
    Second term = First term + 112 = 25 + 121 = 146
    Third term = Second term - 92 = 146 - 81 = 65
    similarly , we can calculate the all next terms .
    Second series :-
    First term = 39
    Second term = First term + 112 = 39 + 121 = 160
    Third term = Second term - 92 = 160 - 81 = 79

    Correct Option: C

    The given series is in the below pattern ,
    First series :-
    First term = 25
    Second term = First term + 112
    Second term = 25 + 112 = 25 + 121 = 146
    Third term = Second term - 92
    Third term = 146 - 92 = 146 - 81 = 65
    similarly , we can calculate the all next terms .
    Second series :-
    First term = 39
    Second term = First term + 112
    Second term = 39 + 112 = 39 + 121 = 160
    Third term = Second term - 92
    Third term = 160 - 92 = 160 - 81 = 79
    Fourth term = Third term + 72
    Fourth term = 79 + 72 = 79 + 49 = 128
    Fifth term = Fourth term - 52
    Fifth term = 128 - 52 = 128 - 25 = 103
    Fifth term = Fourth term - 52
    Sixth term = 103 + 32 = 103 + 9 = 112
    So 112 should come in place of (e).


Direction: In each of these questions a number series is given. Only one number is wrong in each series. You have to find out the wrong number.

  1. 1, 2, 4.5, 11, 30, 92.5, 329
    1. 92.5
    2. 4.5
    3. 11
    4. 2
    5. 30

  1. View Hint View Answer Discuss in Forum

    As per the details in the question the series is in the form of
    First term = 1
    Second term = ( First term × Variable ) + Variable = 2
    Third term = ( Second term × Variable + 0.5 ) + Variable + 0.5 = 4.5

    Correct Option: A

    As per the details in the question the series is in the form of
    First term = 1
    Second term = ( First term × Variable ) + Variable = 2
    Third term = ( Second term × Previous Variable + 0.5 ) + Previous Variable + 0.5 = 4.5
    Similarly we can find the all others terms
    Second term = ( 1 × 1 ) + 1 = 2
    Third term = ( 2 × 1.5 ) + 1.5 = 4.5
    Fourth term = ( 4.5 × 2 ) + 2 = 11
    Fifth term = (11 × 2.5 ) + 2.5 = 30
    Sixth term = ( 30 × 3 ) + 3 = 92.5 , 93 should be sixth term because ( 30 × 3 ) + 3 = 93
    So 92.5 is wrong. we get 93 as 6th term.
    Seventh term = ( 93 × 3.5 ) + 3.5 = 325.5 + 3.5 = 329.



  1. 2, 5, 7, 12, 19, 32, 50
    1. 7
    2. 12
    3. 32
    4. 19
    5. 5

  1. View Hint View Answer Discuss in Forum

    The Order of above given series is
    First term + Second term = Third term
    ⇒ 2 + 5 = 7;
    Second term + Third term = Fourth term
    ⇒ 5 + 7 = 12;
    Third term + Fourth term = Fifth term
    ⇒ 7 + 12 = 19;...

    Correct Option: C

    The Order of above given series is
    First term + Second term = Third term
    ⇒ 2 + 5 = 7;
    Second term + Third term = Fourth term
    ⇒ 5 + 7 = 12;
    Third term + Fourth term = Fifth term
    ⇒ 7 + 12 = 19;...
    Fourth term + Fifth term = Sixth term
    ⇒ 12 + 19 = 32 , 31 should be 6th term because 12 + 19 = 31
    So 32 is wrong. we get 31 as 6th term.
    Fifth term + Sixth term = Seventh term
    ⇒ 19 + 31 = 50


  1. 2, 14, 91, 546, 3002, 15015
    1. 15015
    2. 91
    3. 14
    4. 3002
    5. 546

  1. View Hint View Answer Discuss in Forum

    The given series is in the below pattern,
    First term = 2
    Second term = First term × 7
    Similarly we can calculate next terms also.

    Correct Option: D

    The given series is in the below pattern,
    First term = 2
    Second term = First term × 7
    Second term = 2 × 7 = 14
    Similarly we can find the all others terms also.
    Third term = Second term × 6.5
    Third term = 14 × 6.5 = 91
    Fourth term = Third term × 6
    Fourth term = 91 × 6 = 546
    Fifth term = Fourth term × 5.5
    Fifth term = 546 × 5.5 = 3002 is wrong , So 3003 should be Fifth term because ( 546 × 5.5 ) = 3003 .
    Sixth term = Fifth term × 5
    Fifth term = 3003 × 5 = 15015.



Direction: What will come in the place of question mark (?) in the following number.

  1. 0, 7, 26, 63, ?
    1. 125
    2. 126
    3. 217
    4. 124
    5. None of these

  1. View Hint View Answer Discuss in Forum

    The given series is in the below pattern,we can see that
    Next term ( Tn ) = n3 - 1 { where , putting n = 1 , 2 , 3 , 4 , 5 respectively }

    Correct Option: D

    The given series is in the below pattern,we can see that
    Next term ( Tn ) = n3 - 1 { where , putting n = 1 , 2 , 3 , 4 , 5 respectively }
    First term = T1 = 13 - 1 = 0
    Second term = T2 = 23 - 1 = 7
    Similarly we can find the all others terms
    Third term = 26
    Fourth term = 63
    Fifth term( ? )= 124
    Hence we get the value of ? = 124