10th Class Mental Ability blank Inserting The Missing Character

INSERTING THE MISSING CHARACTER

In such type of problems, a figure/design/table or a group of figures is given. This figure consists of some numbers or letters or both following a certain pattern. In fact, one space for a number letter is left blank which is to be filled up. In order to fill in the blank space a student is required to decipher the pattern.

Trick: To decipher a pattern, use various mathematical operations viz, addition, subtraction, multiplication, division and their combinations.

EXAMPLE

1.         Select the number which will replace the mark'?' in pattern given below.

(a) 64                            (b) 100             

(c) 81                            (d) 144

Explanation: (d)

Figure 1 : \[{{\left[ \left( 8\text{ }+\text{ }4 \right)\text{ }-\text{ }\left( 6\text{ }+\text{ }3 \right) \right]}^{2}}=9\]

Figure 2 : \[{{\left[ \left( 7\text{ }+\text{ }9 \right)\text{ }-\text{ }\left( 5\text{ }+\text{ }4 \right) \right]}^{2}}=49\]

Figure 3 : \[{{\left[ \left( 8\text{ }+\text{ }9 \right)\text{ }-\text{ }\left( 2\text{ }+\text{ }3 \right) \right]}^{2}}=\text{ }144\]

Thus, the required number is 144.

2.         Select a letter from the options which will replace the'?'.

(a) I                                (b) J

(c) K                              (d) L

Explanation: (b)

Let us consider row-wise,

Row 1: \[A+2=C;\text{ }C+2=E;\]

Row 3: \[K+2=M\text{ };\text{ }M+2=0\]

Row 2: \[F+2=H\] So, \[H+2=\{\,J\,\}\]

Thus, the required letter is ?J?.

3.         Find the missing number in the given figure.

(a) 5                              (b) 9              

(c) 11                            (d) 13

Explanation: (b)

Observing the given design, we see that

Place value of W=23 and place value of T=20

Here, 23 - 20 = 3

The same rule is followed by the other two sets.

Thus, place value of P = 16

Place value of G = 7

So, required number =16-7=9.