Number Series Completion - Study Mode

[#81] Which term of the series 5, 8, 11, 14, ....is 320 ?
Correct Answer

(C) 106th

Explanation

Solution: Clearly, 5 + 3 = 8, 8 + 3 = 11, 11 + 3 = 14,................ So, the series in an A.P. in which a = 5 and d = 3 Let 320 be the nth term of the series. Then, 320 = 5 + (n - 1) × 3 or (n - 1) = 105 or n = 106

[#82] Find the missing term: 1, 9, 25, 49, ?, 121
Correct Answer

(B) 81

Explanation

Solution: The given series consists of squares of consecutive odd numbers i.e., 1 2 , 3 2 , 5 2 , 7 2 ,.......... So. missing term = 9 2 = 81

[#83] Find the missing term: 4, 6, 9, 13 1 / 2 , ?
Correct Answer

(C) 20 1 / 4

Explanation

Solution: The pattern is × 3 / 2 . So, missing number = 13 1 / 2 × 3 / 2 = 27 / 2 × 3 / 2 = 81 / 4 = 20 1 / 4 .

[#84] 2, 8, 14, 20, 26, 32, 38, ... choose which pair of numbers comes next?
Correct Answer

(B) 44, 50

Explanation

Solution: This is a simple addition series, which begins with 2 and adds 6.

[#85] 9, 11, 33, 13, 15, 33, 17, ... choose which pair of numbers comes next?
Correct Answer

(A) 19, 33

Explanation

Solution: In this alternating repetition series, a random number, 33, is interpolated every third number into a simple addition series, in which each number increases by 2.