Which two signs and numbers need to be interchanged to make the following equation correct?

24 - (9 ÷ 12) + (84 × 4) + 28 = 23

Here, we use the BODMAS table given below:

Given:

⇒ 24 - (9 ÷ 12) + (84 × 4) + 28 = 23

(1) 24 and 28, - and ÷

⇒ 24 - (9 ÷ 12) + (84 × 4) + 28 = 23

After interchanging the sign and numbers:

⇒ 28 ÷ (9 - 12) + (84 × 4) + 24 = 23

Apply BODMAS rule:

⇒ 28 ÷ (-3) + 336 + 24

⇒ (-9.33) + 336 + 24

⇒ 360 - 9.33 = 350.67

Here, the equation is not satisfied.

(2) 24 and 28, × and ÷

⇒ 24 - (9 ÷ 12) + (84 × 4) + 28 = 23

After interchanging the sign and numbers:

⇒ 28 - (9 × 12) + (84 ÷ 4) + 24 = 23

Apply BODMAS rule:

⇒ 28 - 108 + 21 + 24

⇒ 73 - 108 = (-35)

Here, the equation is not satisfied.

(3) 9 and 4, ÷ and ×

⇒ 24 - (9 ÷ 12) + (84 × 4) + 28 = 23

After interchanging the sign and numbers:

⇒ 24 - (4 × 12) + (84 ÷ 9) + 28 = 23

Apply BODMAS rule:

⇒ 24 - 48 + 9.33 + 28

⇒ 61.33 - 48 = 13.33

Here, the equation is not satisfied.

(4) 12 and 4, ÷ and ×

⇒ 24 - (9 ÷ 12) + (84 × 4) + 28 = 23

After interchanging the sign and numbers:

⇒ 24 - (9 × 4) + (84 ÷ 12) + 28 = 23

Apply BODMAS rule:

⇒ 24 - 36 + 7 + 28

⇒ 59 - 36 = 23

⇒ '24 - (9 × 4) + (84 ÷ 12) + 28 = 23'

Here, the equation is satisfied.

Hence, the correct answer is "Option (4)".