Question 84

Logical Reasoning Alphanumeric series Easy

<p>Which number should come in place of the question mark (?) in the following chart :</p> <table border="1" cellpadding="0" cellspacing="0" style="width: 100px;"> <tbody> <tr> <td> <p style="text-align: center;">1</p> </td> <td> <p style="text-align: center;">7</p> </td> <td> <p style="text-align: center;">9</p> </td> </tr> <tr> <td> <p style="text-align: center;">2</p> </td> <td> <p style="text-align: center;">14</p> </td> <td> <p style="text-align: center;">?</p> </td> </tr> <tr> <td style="width: 30px;"> <p style="text-align: center;">3</p> </td> <td style="width: 30px;"> <p style="text-align: center;">105</p> </td> <td style="width: 30px;"> <p style="text-align: center;">117</p> </td> </tr> </tbody> </table>

(A) 16
(B) 26
(C) 20
(D) 12
View Dynamic Solution & Explanation
Correct Solution: Option D

Step-by-step Solution:

Identifying the Pattern in the Chart

To find the missing number, we need to determine the logical rule that connects the numbers in the grid. The pattern in this chart operates vertically within each column.

The Rule

The number in the third row of each column is calculated by multiplying the numbers from the first and second rows, and then adding the number from the first row again.

The formula is: Row 3 = (Row 1 × Row 2) + Row 1

Verifying the Pattern

Let's check this rule for the completed columns:

  • Column 1: (1 × 2) + 1 = 2 + 1 = 3. This matches the third row.
  • Column 2: (7 × 14) + 7 = 98 + 7 = 105. This also matches the third row.

The rule is consistent.

Finding the Missing Number

Now, we apply the same rule to the third column to find the missing number in the second row (let's call it 'x').

Row 1 value = 9

Row 2 value = x

Row 3 value = 117

Using the formula: (9 × x) + 9 = 117

9x = 117 - 9

9x = 108

x = 108 / 9

x = 12

Conclusion

The number that should come in place of the question mark is 12.