Question

What will come in the place of question mark '(?)' in the following equation, if '-' and '÷' are interchanged and 'x' and '+' are interchanged ? 8 + 63 - 7 x 7 ÷ 9 = ?

• A. 68
• B. 69
• C. 70
• D. 71

Answer 1

Answer:

C. 70

First, interchange the operators as instructed:

• ‘+’ ↔ ‘x’

• ‘−’ ↔ ‘÷’

8 + 63 − 7 × 7 ÷ 9

So the new expression is:
$8 × 63 ÷ 7 + 7 − 9$
Now solve using BODMAS:

1. (8 × 63 = 504)

2. (504 ÷ 7 = 72)

3. (72 + 7 = 79)

4. (79 − 9 = 70)

$=\boxed{70}$