Mathematical Operations - Interchanging of Symbols


 
 
Concept Explanation
 

Mathematical Operations - Interchanging of Symbols

Mathematical Operations:  As you know that in the questions based on simple mathematical operations the four fundamental mathematical operations that is addition, subtraction, multiplication and division and relational operators that is less that, more than etc are to be rearranged to get the desired result.

Making Equation Correct by Interchanging the Symbols: In these type of questions certain equations are written and the candidate is asked to interchange the position of the symbols or numbers so that the equation becomes correct.

Illustration: In the following question , the given equation becomes correct after interchanging two signs. One of the four alternatives under it specifies the interchange of signs in the equation which when made will make the equation correct. Find the correct alternative.

9+5div 4times 3-6=12

A. + and x                 B. div and x                 C. div and -                    D. + and -

Answer: C

Solution: On interchanging div and -, we get

L.H.S.=9+5-4times3div6

=9+5-4times frac{1}{2}

= 9 + 5 -2

= 12 = R.H.S.

Illustration: In the following question , the given equation becomes correct after interchanging two signs. One of the four alternatives under it specifies the interchange of signs in the equation which when made will make the equation correct. Find the correct alternative.

 (6-3) + (4 times 2 + 13)div (7 times 2)=21

A.  + and -                   B. times ;; and ;; div                    C.  div ;; and ;; +              D.  times ;; and ;; -

Answer : D

Solution: On interchanging times ;; and ;; -, we get

(6-3) + (4 times 2 + 13)div (7 times 2)=21

L.H.S. = (6times3) + (4-2 + 13)div (7 - 2)

= 18 + 15div 5

= 18 + 3 = 21= R.H.S.

Illustration: If the given interchanges namely : signs + and div and numbers 2 and 4 are made in signs and numbers, which one of the following four equations would be correct ?

(a)  2 + 4 div 3 = 3                  (b)  4 + 2 div 6 = 15               (c)  4 div 2 + 3 = 4             (d) 2 + 4 div 6 = 8

Answer: D

Solution : - on interchanging (+ and div) and (2 and 4), we get,

(a)  4 div 2 + 3 = 3 ;; or ;; 5=3, which is false.

(b)  2 div 4 +6 =1.5 ;; or ;; 6.5=1.5,  which is false

(c)  2 + 4 div 3 = 4 ; ; or ;; frac {10}{3}=4,  which is false.

(d)  4 div 2 + 6 =8 ;; or ;; 8=8, which is true. 

Hence, the answer is (d).

Sample Questions
(More Questions for each concept available in Login)
Question : 1

If 20 - 10 means 200, 8 div 4 means 12, 6 X 2 means 4, then 100 - 10 X 1000 div 1000 + 100 X 10 = ?

Right Option : A
View Explanation
Explanation
Question : 2

The given equation becomes correct due to the interchange of two signs. one of the four options specifies the interchange of signs in the equation which when made will make the equation correct. Find the correct option.

5 + 3 times 8 - 12 div 4 = 3

Right Option : B
View Explanation
Explanation
Question : 3

In each of the following questions, which one of  the four interchanges in signs and numbers would make the given equation correct?

(6 small div 2 ) small times3 = 0

Right Option : D
View Explanation
Explanation
 
Video Link - Have a look !!!
 
Language - Hindi/English
 
Chapters
Content / Category
Class / Course
 
 
Related Videos



Students / Parents Reviews [10]