Which two signs should be interchanged to make the given equation correct?
30 + 6 × 4 ÷ 2 - 1 = 21
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. ÷ and +
30 + 6 × 4 ÷ 2 - 1 = 21
From option 1, by interchanging signs ÷ and +, we get
(30 ÷ 6) × 4 + 2 - 1 = 21
⇒ (5 × 4) + 2 - 1 = 21
⇒ (20 + 2) - 1 = 21
⇒ 22 - 1 = 21
⇒ 21 = 21
As we have found our answer, so, there is no need of checking other options.
Hence, the correct answer is ÷ and +.