Coding and Decoding Questions

If 'x' means 'addition', '­' means 'division', '/' means 'subtraction' and '+' means 'multiplication', then which of the equation is correct

In a certain code language, '-' represents '+', '+' represents 'x', 'x' represents '÷' and '÷' represents '-'. Find out the answer to the following question.

10 + 20 x 10 ÷ 20 - 8 = ?

In a certain code language, '+' represents 'x', '-' represents '+', 'x' represents '÷' and '÷' represents '-'. What is the answer to the following question?

50 + 3 ÷ 125 x 5 - 25 = ?

If 70$7 = -10, 50$5 = -10 and 40$8 = -5, then find the value of 10$2 = ?

Some equations are solved on the basis of certain system. Find the correct answer for the unsolved equation on that basis.

5 x 4 x 3 = 70 ,
6 x 5 x 4 = 140
7 x 6 x 5 = ?

If 80&10 = -8, 50&2 = -25 and 80&16 = -5, then find the value of 20&5 = ?

In a certain code language, “LINKS” is written as “93210” and “CROMA” is written as “84576”. How is “ROCKS” written in that code language?

If 15#2 = 26, 11#3 = 16 and 10#9 = 2, then find the value of 11#4 = ?