In a certain coding language, 'Ginger is a root' is written as 4123, 'A tree has a root' is 75422 and 'Tree is green' is 385. Which digit represents 'root'?
In a certain code language, 'x' represents '+', '÷' represents 'x', '-' represents '÷' and '+' represents '-'. Find out the answer to the following question.