Practice Questions: Series Completion and Inserting

Q1: Direction: In the following question, a series is given. One figure of this series is missing. Fill in the blanks to complete this series.

(a)

(b)

(c)

(d)

Ans: (b)

Explanation: In every step one small square is removed alternately from the rightmost column and then from the bottom row. Following this alternating removal, option (b) is the figure that correctly shows the next stage.

Q2: Direction: In the following question, a series is given. One figure of this series is missing. Fill in the blanks to complete this series.

(a)

(b)

(c)

(d)

Ans: (a)

Explanation: A small square is added inside the figure at each step and the shading of that inner square alternates each time. Option (a) correctly continues this pattern of adding a square with the alternate shade.

Q3: Direction: In the following question, a series is given. One figure of this series is missing. Fill in the blanks to complete this series.

(a)

(b)

(c)

(d)

Ans: (c)

Explanation: At each step one bar and one dot are added. The dot is placed next to the most recently added bar, and the dot position alternates between the bottom and the top. Option (c) is the only choice that continues this alternating placement correctly.

Q4: Direction: In the following question, a series is given. One figure of this series is missing. Fill in the blanks to complete this series.

(a)

(b)

(c)

(d)

Ans: (b)

Explanation: The polygon in each step gains one side compared with the previous figure (for example a triangle → quadrilateral → pentagon, and so on). Option (b) correctly shows the next figure with one additional side.

Q5: Direction: Find the number which will replace the '?' mark.

(a) 22
(b) 30
(c) 32
(d) 31

Ans: (c)

Sol: The relation shown in the figure is given by:

Using that relation to calculate the missing entry gives:

Q6: Direction: In the following question, a series is given. A term in series is missing. Find the missing term from amongst the options.
18, 17, 19, ?, 20, 15, 21, 14
(a) 16
(b) 17
(c) 18
(d) 19
Ans: (a) 16
Sol: Observe the pattern of alternating subtracting and adding with increasing amounts:
18 - 1 = 17
17 + 2 = 19
19 - 3 = 16 ← missing term
16 + 4 = 20
20 - 5 = 15
15 + 6 = 21
21 - 7 = 14
Therefore, the missing term is 16.

Q7: Direction: In the following question, a series is given. A term in series is missing. Find the missing term from amongst the options.
1, 5, 13, 25, 41, ?
(a) 52
(b) 58
(c) 61
(d) 62
Ans: (c) 61
Sol: Examine the differences between consecutive terms:

• 5 - 1 = 4
• 13 - 5 = 8
• 25 - 13 = 12
• 41 - 25 = 16

These differences increase by 4 each time (4, 8, 12, 16). The next difference will be 16 + 4 = 20. So the next term = 41 + 20 = 61.

Q8: Direction: In the following question, a series is given. A term in series is missing. Find the missing term from amongst the options.
10, 18, 28, 40, 54, 70, ?
(a) 85
(b) 86
(c) 87
(d) 88
Ans: (d) 88
Sol: Find consecutive differences:
18 - 10 = 8
28 - 18 = 10
40 - 28 = 12
54 - 40 = 14
70 - 54 = 16
Differences increase by 2 each time. Next difference = 16 + 2 = 18. Therefore next term = 70 + 18 = 88.

Q9: Direction: In the following question, a series is given. A term in series is missing. Find the missing term from amongst the options.
6, 11, 21, 36, 56, ?
(a) 42
(b) 51
(c) 81
(d) 91
Ans: (c) 81
Sol: Compute differences:
11 - 6 = 5
21 - 11 = 10
36 - 21 = 15
56 - 36 = 20
Differences increase by 5 each time (5, 10, 15, 20). Next difference = 20 + 5 = 25. So next term = 56 + 25 = 81.

Q10: Direction: In the following question, a series is given. A term in series is missing. Find the missing term from amongst the options.
2, 5, 9, ?, 20, 27
(a) 14
(b) 16
(c) 18
(d) 24
Ans: (a) 14
Sol: Look at the differences between consecutive terms:
5 - 2 = 3
9 - 5 = 4
So differences appear to increase by 1 each time. Next difference = 4 + 1 = 5. Therefore the missing term = 9 + 5 = 14.