Question

What will come in the place of the question mark (?) in the following equation, if '+' and 'x' are interchanged and '÷' and '-' are interchanged? 15÷5+8-4×7=?

• A. 18
• B. 25
• C. 22
• D. 12

Answer 1

Answer:

D. 12

Given expression:
$15 \div 5 + 8 - 4 \times 7$

Apply the interchange rules

• (+) ↔ ( \times )

• ( \div ) ↔ ( - )

So the expression becomes:
$15 - 5 \times 8 \div 4 + 7$
Apply BODMAS

First multiplication/division:
$5 \times 8 = 40$
$40 \div 4 = 10$

Now expression:
$15 - 10 + 7$

Solve

$15 - 10 = 5$
$5 + 7 = 12$

Final Answer:

12