Which two numbers should be interchanged to make the given equation correct?

108 ÷ 6 - 18 + 8 × 9 = 42

The logic followed here is :-

By using BODMAS RULE :

Option 1) : 108 and 18

Given equation is  : 108 ÷ 6 - 18 + 8 × 9 = 42

After interchanging the two numbers the equation is as follows : 18 ÷ 6 - 108 + 8 × 9 = 42

⇒ 18 ÷ 6 - 108 + 8 × 9 = 42

⇒ 3 - 108 + 8 × 9 = 42

⇒ 3 - 108 + 72 = 42

⇒ 75 - 108 = 42

⇒ - 33 ≠ 42

LHS ≠ RHS

Option 2) : 9 and 6

Given equation is  : 108 ÷ 6 - 18 + 8 × 9 = 42

After interchanging the two numbers the equation is as follows : 108 ÷ 9 - 18 + 8 × 6 = 42

⇒ 108 ÷ 9 - 18 + 8 × 6 = 42

⇒ 12 - 18 + 8 × 6 = 42

⇒ 12 - 18 + 48 = 42

⇒ 60 - 18 = 42

⇒ 42 = 42

LHS = RHS

Option 3) : 18 and 9

Given equation is  : 108 ÷ 6 - 18 + 8 × 9 = 42

After interchanging the two numbers the equation is as follows : 108 ÷ 6 - 9 + 8 × 18 = 42

⇒ 108 ÷ 6 - 9 + 8 × 18 = 42

⇒ 18 - 9 + 8 × 18 = 42

⇒ 18 - 9 + 144 = 42

⇒ 162 - 9 = 42

⇒ 153 ≠ 42

LHS ≠ RHS

Option 4) : 6 and 8

Given equation is  : 108 ÷ 6 - 18 + 8 × 9 = 42

After interchanging the two numbers the equation is as follows : 108 ÷ 8 - 18 + 6 × 9 = 42

⇒ 108 ÷ 8 - 18 + 6 × 9 = 42

⇒ 13.5 - 18 + 6 × 9 = 42

⇒ 13.5 - 18 + 54 = 42

⇒ 67.5 - 18 = 42

⇒ 49.5 ≠ 42

LHS ≠ RHS

Hence, the correct answer is "9 and 6".