In each of the following questions, a number series is given with one term missing. Choose the correct alternative that will continue the same pattern.
5,6,9, 15, ?, 40
Answer: B
Explanation:The pattern is + 1, + 3, + 6,….., i.e. + 1, + (1, + 2), + (1 + 2 + 3),…..So, missing term = 15 + (1 + 2 + 3 + 4) = 25.
Enter details here
6, 13, 25, 51, 101, ?
Answer: C
Explanation:The pattern is x 2 + 1, x 2 – 1, x 2 + 1, x 2 – 1,…..So, missing term = 101 x 2 + 1 = 203.
Enter details here
1, 2, 3, 6, 9, 18, ?, 54
Answer: B
Explanation:The pattern is x 2, x 3/2, x 2, x 3/2, x 2,…..So, missing term = 18 x 3/2 = 27
Enter details here
Which term of the series 5, 10, 20, 40, ..... is 1280?
Answer: B
Clearly, 5 x 2 = 10, 10 x 2 = 20, 20 x 2 = 40,.....
So, the series is a G.P. in which a = 5 and r = 2.
Let 1280 be the rath term of the series.
Then, 5x2n-1 = 1280 2n-1 = 256 = 28 n - 1 = 8 n = 9.
Enter details here
1, 9, 25, 49, ?, 121
Answer: B
Explanation:
The given series consists of squares of consecutive odd numbers
So, missing term = square of 9 = 81.
Enter details here
1, 9, 25, 49, 81, ?
Answer: C
Explanation:
The series consists of squares of consecutive odd number
So, missing term = square of 11 = 121.
Enter details here
28, 33, 31, 36, ?, 39
Answer: B
Explanation:
The pattern is + 5, - 2, + 5, - 2,.....
So, missing term = 36 - 2 = 34.
Enter details here
66, 36, 18, ?
Answer: C
Explanation:
Each term in the series is the product of the digits of the preceding term.
So, missing term = 1 x 8 = 8.
Enter details here
125,80,45,20,?
Answer: A
Explanation:The pattern is – 45, – 35, – 25, …..So, missing term = 20 – 15 = 5.
Enter details here
In the series 2, 6, 18, 54, …… what will be the 8th term ?
Answer: B
Explanation:Clearly, 2 x 3 = 6, 6 x 3 = 18, 18 x 3 = 54,…..So, the series is a G.P. in which a = 2, r = 3.Therefore 8th term = ar8-1 = ar7 = 2 x 37 = (2 x 2187) = 4374.
Enter details here