Olympiad Test: Series Completion - 3 - Class 8 MCQ

The series is aa/bcab/bcab/ccaa/bcab/bc Thus, the pattern ccaa followed by bcab repeated twice, makes up the series.

The series is bccb/bccb/bccb
Thus, the pattern bccb is repeated.

The series is aaa/bbb/aaa/bbb/aaa/bbb
Thus, the pattern aaa, bbb is repeated.

The series is aabcbba/aabcbba/aabcbba Thus, the pattern aabcbba is repeated.

The series is adbca/cbdabc/ddcd/adbca/cbda. Here, the letters equidistant from the beginning and the end of the series are the same.

The series is aaa/bbbb/cccc/dddd/cccc/bbbb/a.

The series is aaba/bcabc/ddbac/babaa Thus, the letters equidistant from the beginning and the end of the series are the same.

The series is tsr/str/tsr/str/tsr/str.
Thus,the pattern tsr/str is repeated.

The series is baa/baa/baa/baa. Thus, the pattern baa is repeated.

The series is ababc/bcbca/cacab.

Each number is double the preceding one plus 1.
So, the next number is (255 x 2) + 1 = 511.

The sequence is 1 x 2, 2 x 3, 3 x 4, 4 x´ 5, 5 x 6, 6 x 7, 7 x 8.
∴ Next number = 8 x 9 = 72

Each number is 15 multiplied by a prime number i.e. 15 x 11, 15 x 13, 15 x 17, 15 x 19, 15 x 23
∴ Missing term = 15 x 29 = 435

There are two series: 10, 13, 16, 19 and 5, 10, 20, …….
∴ Missing number = 40

Alternately 5 is added and 7 is subtracted.
Thus, 71, 74 - 7 = 67 and so on
∴ Missing number = 72 - 7 = 65

The terms of the series are 2² - 1, 4² - 1, 6² - 1, ……, 10² - 1, 12² - 1.

The given sequence is a combination of two series 6, 12, 18 24 and 24, ……, 8.
Clearly, the first series consists of consecutive multiples of 6 and the second series consists of multiples of 8. Thus, 
∴ Missing number 25 + 4 = 29

The sequence is -11, -13, -15, -13, ……
∴ Missing number = 45 - 11 = 34

The sequence is + 4, + 5, + 6, ……
∴ Missing number = 17 + 7 = 24

The sequence is + 2, + 4, + 2, + 4, +2, ……