# Series Practice test

1.

Complete the series 26, 19, 17, 13, 11, ?, 8, 7

Explanation:

26, 17,11, 8 these are decreasing like 9, 6, and 3
19, 13, 9, and 7 these are decreasing like 6, 4, and 2

2.

Look at this series: 4, 7, 25, 10, __, 20, 16, 19… What number should fill the blank?

Explanation:

Two series alternate here, with every third number following a different pattern.
In the main series, 3 are added to each number to arrive at the next.
In the alternating series, 5 is subtracted from each number to arrive at the next.

3.

Find odd number from series 8, 27, 64, 100, 125, 216, 343

Explanation:

The pattern is 2^3, 3^3, 4^3, 5^3, 6^3, 7^3.
But, 100 is not a perfect cube.

4.

3,15,35,63,_____

Explanation:

3*5 =15

5*7 = 35

7*9 = 63

9*11 = 99

5.

1,1,2,6,24,____

Explanation:

1*1 = 1

1* 2 = 2

2*3 = 6

6*4 = 24

6.

101,122,145,_____

Explanation:

101 + 21 = 122

122 + 23 = 145

145 + 25 = 170

7.

8, 7, 11, 12, 14, 17, 17, 22, (….)

Explanation:

There are two series (8, 11, 14, 17, 20) and (7, 12, 17, 22) increasing by 3 and 5 respectively.

8.

9, 11, 20, 31, (…..), 82

Explanation:

Each term in the series is the sum of the preceding two terms.

Missing number = 20 + 31 = 51.

9.

Given the sequence A, BB, CCC, DDDD………..and so on , the 240th letter in the sequence will be: