If '+' and '-' are interchanged and also the numbers 8 and 6 change places, which of the
12 + 6 - 8 = 10
The question asks us to apply specific rules of interchange to mathematical expressions and then determine which of the given options remains correct after these changes. The rules for interchange are:
This means wherever a '+' appears, it becomes '-', and wherever a '-' appears, it becomes '+'. Similarly, wherever '8' appears, it becomes '6', and wherever '6' appears, it becomes '8'. Other numbers and operators remain unchanged.
Let's go through each given option and apply the specified interchanges to the expression on the left side of the equality sign. We will then evaluate the new expression and compare it to the original result on the right side.
Let's summarize the results in a table for clarity:
| Original Option | Interchanges Applied ( '+' $\leftrightarrow$ '-', '8' $\leftrightarrow$ '6' ) | Modified Expression Evaluation | Original Result | Correct? |
|---|---|---|---|---|
| $6 - 8 - 8 + 8 = 0$ | $8 + 6 + 6 - 6$ | $14$ | $0$ | No |
| $12 + 8 - 6 = 2$ | $12 - 6 + 8$ | $14$ | $2$ | No |
| $12 + 6 - 8 = 10$ | $12 - 8 + 6$ | $10$ | $10$ | Yes |
| $6 - 4 + 8 - 8 = 6$ | $8 + 4 - 6 + 6$ | $12$ | $6$ | No |
Based on the evaluations, only Option 3 results in the original equality holding true after applying the given interchanges.
When operators and numbers are interchanged according to the specific rules provided in the question, we must carefully substitute each instance of the specified operators and numbers in the given expressions. After performing these substitutions, we evaluate the new mathematical expression. The option for which the evaluated result matches the original result stated in the option is the correct answer.
| Concept | Explanation | Importance in this Problem |
|---|---|---|
| Interchange Rules | Specific rules defining which symbols/numbers swap places or meanings. | Crucial for correctly transforming the expressions. |
| Order of Operations | Rules like PEMDAS/BODMAS for evaluating expressions (although in this problem, simple addition/subtraction from left to right is sufficient). | Ensures correct calculation of the modified expression. |
| Equality | The state where the value of the expression on the left side equals the value on the right side. | The condition that must remain true after interchanges for an option to be correct. |
Problems involving interchanging symbols or numbers are common in logical reasoning or mathematical puzzle sections of exams. They test your ability to follow instructions precisely and apply transformations consistently. Here are some related concepts:
In this specific problem, the interchange is straightforward: '+' and '-' swap, and '8' and '6' swap. The key is systematic application of these rules to each part of the equation and then correctly performing the arithmetic.
Which two numbers should be interchanged to make the given equation correct?
9 + 7 × 5 – 18 ÷ 2 = 3 × 4 – 10 + 45 ÷ 5Select the correct combination of mathematical signs that can sequentially replace the * signs and balance the equation.
60 * 2 * 3 * 6 * 5 * 43
Which of the following interchange of numbers and mathematical signs would make the given equation correct?
30 ÷ 6 × 4 + 15 - 35 = 25
Which two signs need to be interchanged to make the following equation correct?
23 + 84 ÷ 14 × 8 − 3 = 5
Select the correct combination of mathematical signs that can sequentially replace the * signs and make the equation correct.
68 * 138* 23 * 54 * 20