Inserting the Missing Character Notes for SSC Exams

In inserting the missing character questions, numbers or letters are given in a figure, a grid or a triangle, and one place is empty. You must find the rule used in the other rows or figures and fill the empty place. These inserting the missing character notes for SSC list the common rules, a step-by-step method and solved examples.

Common Figures

Common Rules

Method to Find the Rule

1. Take the row or figure that is complete.
2. Try the sum, difference, product and division of the numbers.
3. Try the square or cube of a number.
4. Check the same rule on the second complete row or figure.
5. Apply the rule to the row with the missing number.

Solved Examples

Example 1. 2, 3, 6; 4, 5, 20; 6, 7, ?
The third number is the product of the first two (2 × 3 = 6, 4 × 5 = 20). So 6 × 7 = 42.

Example 2. 3, 5, 8; 6, 4, 10; 7, 9, ?
The third number is the sum of the first two. So 7 + 9 = 16.

Example 3. 2 → 4; 3 → 9; 4 → ?
The second number is the square of the first. So 4 × 4 = 16.

Example 4. A, C, 4; B, D, 6; E, G, ?
Use the positions of the letters. A (1) + C (3) = 4, and B (2) + D (4) = 6. For E (5) + G (7) the answer is 12.

Example 5 (triangle). The outer numbers 2, 5, 3 have 10 in the centre. The outer numbers 4, 6, 2 have 12 in the centre. The outer numbers 3, 7, 4 have ? in the centre.
The centre is the sum of the three outer numbers (2 + 5 + 3 = 10, and 4 + 6 + 2 = 12). So 3 + 7 + 4 = 14.

Useful Squares and Cubes

Common Mistakes

• Checking the rule on only one row.
• Mixing up the order of the numbers in a subtraction.
• Using the position from the wrong end for letters.
• Not trying the column when the row does not give a rule.

Quick Tips

• Always check the rule on at least two rows or figures.
• If the row does not work, try the columns.
• Learn the squares up to 20 and the cubes up to 10.
• For letters, change them into numbers first.

Quick Revision Points

• Try sum, difference, product and division first.
• Then try square, cube and sum of squares.
• Check the same rule on all complete rows.
• Rows first, columns next.
• For letters, use the alphabet positions.

Practice Questions With Answers

1. 3, 4, 12; 5, 6, 30; 7, 8, ?
   Answer: 56
2. 2, 6, 8; 3, 7, 10; 4, 9, ?
   Answer: 13
3. 5 → 25; 6 → 36; 7 → ?
   Answer: 49
4. 10, 4, 6; 15, 9, 6; 20, 12, ?
   Answer: 8
5. C, D, 7; E, F, 11; G, H, ?
   Answer: 15
6. 2 → 8; 3 → 27; 4 → ?
   Answer: 64
7. 4, 2, 2; 12, 3, 4; 20, 5, ?
   Answer: 4
8. 2, 3, 13; 3, 4, 25; 4, 5, ?
   Answer: 41
9. Triangle: outer 1, 2, 3 has 6 in the centre; outer 2, 3, 4 has 9; outer 5, 6, 7 has ?
   Answer: 18
10. Which operations should you try first on the numbers of a row?
    Answer: Sum, difference, product and division, then square and cube

How to Practise This Chapter

Practise ten questions daily and keep a small notebook of the rules. Then attempt timed sets from our practice papers and the previous year papers page. See all topics on the Verbal Reasoning notes page, and also read the Coding-Decoding and Reasoning notes. Read the previous topic, Dictionary Order and Word Arrangement, and the next topic, Hidden Words.

Frequently Asked Questions

What is inserting the missing character?

It is a reasoning question where a number or letter is missing in a figure and you must find it by the rule of the other parts.

How do I find the rule?

Try the sum, difference, product, division, square and cube on the complete row or figure.

Should I check rows or columns first?

Check the rows first, and if there is no rule, check the columns.

How many rows should I check?

At least two complete rows or figures, to be sure the rule is correct.

How do I solve letter-based missing characters?

Change the letters into their alphabet positions and apply the number rule.

What is the rule in a triangle?

Usually the centre number is the sum, the product or a mix of the outer numbers.

Which squares should I learn?

Learn the squares up to 20 and the cubes up to 10.

Is this topic asked in SSC exams?

Yes. Missing number and character questions are asked in SSC reasoning papers.

How much time should I take for one question?

About 40 seconds.

What are common mistakes?

Checking only one row and making mistakes in subtraction order.

Do these questions have more than one rule?

Sometimes a mixed rule is used, such as multiply and then add, so try combinations if one operation fails.

How many questions come from this topic in SSC exams?

Usually one or two questions come from this topic, but the number changes from year to year.