Coding and Decoding Questions

If '+' and 'x' signs as well as '3' and '2' are interchanged, which of the one following is correct?

In a certain code language, "RAINBOW" is written as "1987645" and "SNAP" is written as "3790". How is "PIANO" written in that code language?

If ENCRYPT is coded as VMXIBKG, then how will ARC be coded as?

In a certain code language, "NIGHT" is written as "ODDGM" and "DARK" is written as "GOYC". How is "GREEN" written in that code language?

Which of the following interchanges in signs will make the given equation correct?
17- 15 x 5 = 250

In a certain code language, "MATERIAL" is written as "RIALMATE". How is "REMEMBER" written in that code language?

If 17@1=8; 9@1=4; 6@4=1; then what is the value of 8@2=?

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

2 - 12 + 10 x 5 ÷ 12 = ?