What will come in the place of the question mark (?) in the following equation, if ‘+’ and ‘−’ are interchanged and ‘×’ and ‘÷’ are interchanged?
21 − 7 ÷ 144 × 3 + 18 = ?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 339.
Given: 21 − 7 ÷ 144 × 3 + 18 = ?
if ‘+’ and ‘−’ are interchanged and ‘×’ and ‘÷’ are interchanged
After interchanging the signs,
⇒ 21 + 7 × (144 ÷ 3) - 18 = ?
⇒ 21 + (7 × 48) - 18 = ?
⇒ (21 + 336) - 18 = ?
⇒ 339 = ?