Question

If ‘$+$’ means ‘$-$’, ‘$-$’ means ‘$+$’, ‘$\times$’ means ‘$\div$’, and ‘$\div$’ means ‘$\times$’, what will come in place of the question mark (?) in the following equation?

$15 - 8 + 7 \div 6 \times 3 = \text{?}$

• A. 10
• B. 12
• C. 6
• D. 9

Answer 1

Answer:

D. 9

The correct answer is 9.

1. Decode the Operators:
   Change the signs according to the rules given in the question:

   • − becomes +

   • + becomes −

   • ÷ becomes ×

   • × becomes ÷

2. Rewrite the Equation:

   • Original: $15 - 8 + 7 \div 6 \times 3$

   • New: $15 + 8 - 7 \times 6 \div 3$

3. Solve using DMAS (Division, Multiplication, Addition, Subtraction):

   • Division: $6 \div 3 = 2$ $\rightarrow$ Equation becomes: $15 + 8 - 7 \times 2$

   • Multiplication: $7 \times 2 = 14$ $\rightarrow$ Equation becomes: $15 + 8 - 14$

   • Addition: $15 + 8 = 23$ $\rightarrow$ Equation becomes: $23 - 14$

   • Subtraction: $23 - 14 = 9$