2. MATHEMATICAL LOGIC
2.1 Introduction
In this type of test artificial values are allotted in place of digits and signs. In question it is asked to simplify them. In order to
solve the question first of all artificial values are replaced by actual values. In simplification ‘BODMAS’ rule is used.
Here ‘BODMAS’ means as
B for bracket, O for of, D for division, M for multiplication, A for addition and S for subtraction.
Example 1
If ‘a’ means’+’, ‘b’ means ‘-’, ‘c’ means ‘’ and ‘d’ means ‘’ then the expression 16a 4b 3c 4d2 = ?
(A) 10 (B) 17 (C) 18.5 (D)
Answer with explanation (C) : After putting the proper signs, we get
Example 2.
If + means , means, -, - means and means + then 18 4 + 3 2 - 5 = ?
(A) 45 (B) 48
(C) 35 (D) None of these
Answer with explanation (D) : After putting the actual signs for artificial signs we get
EXERCISE-I
1. If ‘’ means ‘-’, ‘+’ means ‘’ , ‘-’ means ‘+’ and ‘’ means ‘’ then 64 4 + 5 - 4 2 = ?
(A) (B) 259 (C) 82 (D) None of these
2. If ‘a’ means ‘’, ‘b’ means ‘+’, ‘c’ means ‘’ and ‘d’ means ‘-’ then 20a 4b 4c 2d 3 = ?
(A) 79 (B) 39 (C) 86 (D) 76
3. If ‘+’ means ‘’, ‘’ means ‘’, ‘x’ means ‘-’ and ‘-’ means ‘+’ then 24 + 6 2 3 - 4 = ?
(A) 6 (B) 4 (C) 8 (D) 2
4. If a, b means ‘’ or ‘+’, c, d means ‘-’ or ‘’ ; b, c means ‘+’ or ‘-’ and a, c means ‘’ or ‘-’ then 10a 2b 4c 8d 6 = ?
(A) 6 (B) 57 (C) 39 (D) None of these
5. If ‘’ means ‘-’, ‘-’ means ‘’, ‘’ means ‘+’ and ‘+’ means ‘’ then 20 60 40 - 20 + 10 = ?
(A) 40 (B) 0 (C) 80 (D) 60
Directions- In each of the questions from 6 to 10, english letters are used for various symbols:
‘B’ for addition, ‘G’ for subtraction, ‘E’ for multiplication, ‘C’ for division , ‘D’ for equal, ‘A’ for > and ‘F’ for <.
Which one of the four expressions is correct ?
6. (A) 18 C 3 D 6 B 8 C 4 G 12 (B) 18 A 13 B 16 E 8 G 4 E 12
(C) 18 C 3 G 6 B 8 B 4 D 12 (D) 18 A 3 E 6 B 8 G 4 B 12
7. (A) 8 B 2 C 6 E 12 F 15 G 10 (B) 8 B 2 B 6 A 12 E 15 C 10
(C) 8 G 2 B 6 A 12 C 15 E 10 (D) 8 C 2 E 6 C 12 B 15 D 10
8. (A) 4 C 2 G 7 B 21 F 9 B 3 (B) 4 E 2 B 7 D 21 B 9 C 3
(C) 4 A 2 B 7 G 21B 9 E 3 (D) 4 C 2 B 7 A 21 C 9 E 3
9. (A) 15 C 15 B 8 F 4 B 6 C 3 (B) 15 C 5 F 8 C 4 B 6 C 3
(C) 15 A 5 E 8 C 4 B 6 E 3 (D) 15 B 5 G 8 B 4 G 6 F 3
10. (A) 10 G 15 B 6 A 4 C 8 E 16 (B) 10 C 15 E 6 A 4 G 8 B 16
(C) 10 B 15 C 6 E 4 D 8 B 16 (D) 10 C 15 E 6 B 4 B 8 D 16
Directions - (Q. 11-16) In each of the questions
