Question

What will come in the place of the question mark (?) in the following equation if ‘+’ and ‘×’ are interchanged and ‘−’ and ‘÷’ are interchanged? 81 − 9 + 6 ÷ 36 × 13 = ?

• A. 112
• B. 151
• C. 103
• D. 31

Answer 1

Answer:

D. 31

31 will come in place of the question mark (?).

1. Interchange the signs as instructed:

   • '−' becomes '÷'

   • '+' becomes '×'

   • '÷' becomes '−'

   • '×' becomes '+'

2. Rewrite the equation with the new signs:
   $81\div 9\times 6-36+13=?$

3. Solve using the BODMAS rule (Division, Multiplication, Addition, Subtraction):

   • Division: $81 \div 9 = 9$
     $\rightarrow 9\times 6-36+13$

   • Multiplication: $9 \times 6 = 54$
     $\rightarrow 54-36+13$

   • Addition & Subtraction: 54 - 36 + 13 = 18 + 13 =31