If P denotes '÷', Q denotes 'x', R denotes '+' and S denotes '-' then 18 Q 12 P 4 R 5 S 6 =?

Given Question is 18 Q 12 P 4 R 5 S 6
After changing the letters in to signs as per given in the question, we have
18 x 12 ÷ 4 + 5 - 6 ,
Apply the BODMAS Rule,
⇒ 18 x 12/4 + 5 - 6
⇒ 18 x 3 + 5 - 6
⇒ 54 + 5 - 6
∴ 59 - 6 = 53