By Interchanging the given two numbers which of the following equation will be not correct?
1 and 9
Analyze Equation Validity After Interchanging 1 and 9
The question asks to identify which equation becomes incorrect when the digits 1 and 9 are swapped.
Step 1: Interchange Digits in Each Option
We will replace every '1' with '9' and every '9' with '1' in each given equation.
Step 2: Evaluate Each Modified Equation
Option 1: Original Equation $9 \times 2 - 1 + 8 = 1$
After interchanging 1 and 9, the equation becomes:
Evaluating the expression:
The result is $1$, which matches the right side ($1 = 1$). This equation remains correct.
Option 2: Original Equation $9 \times 2 + 1 - 4 = 7$
After interchanging 1 and 9, the equation becomes:
Evaluating the expression:
The result is $7$, which matches the right side ($7 = 7$). This equation remains correct.
Option 3: Original Equation $9 - 1 + 7 = -3$
After interchanging 1 and 9, the equation becomes:
Evaluating the expression:
The result is $-1$. The right side is $-3$. Since $-1 \neq -3$, this equation becomes incorrect.
Option 4: Original Equation $1 + 9 \times 3 - 4 = 8$
After interchanging 1 and 9, the equation becomes:
Evaluating the expression (following order of operations):
The result is $8$, which matches the right side ($8 = 8$). This equation remains correct.
Conclusion
The equation that becomes incorrect after interchanging the numbers 1 and 9 is Option 3 ($1 - 9 + 7 = -1$, which does not equal $-3$).
Important Questions from Mathematical Operations
What will come in the place of ‘?’ in the following equation if ‘+’ and ‘−’ are interchanged and ‘×’ and ‘÷’ are interchanged?
18 ÷ 9 + 24 × 3 − 16 = ?If ‘A’ stands for ‘÷’, ‘B’ stands for ‘×’, ‘C’ stands for ‘+’, and ‘D’ stands for ‘−’, what will come in place of the question mark (?) in the following equation?
88 B 3 D 12 A 4 C 6 = ?Select the set in which the numbers are related in the same way as are the numbers of the given sets.
(NOTE: Operations should be performed on whole numbers without breaking down the numbers into their constituent digits. E.g., 13 – Operations on 13 such as adding/subtracting/multiplying, etc., to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed.)
Given sets:
(9, 21, 193)
(12, 15, 184)What will come in the place of the question mark (?) in the following equation, if ‘÷’ and ‘+’ are interchanged and ‘−’ and ‘×’ are interchanged?
44 ÷ 78 + 6 − 3 × 19 = ?Two sets of numbers are given below. In each set of numbers, certain mathematical operation(s) on the first number result(s) in the second number. Similarly, certain mathematical operation(s) on the second number result(s) in the third number and so on. Which of the given options follows the same set of operations as in the given sets?
(NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into their constituent digits. E.g. 13 – Operations on 13 such as adding/subtracting/multiplying to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed.)
