Coding and Decoding Questions

If in a certain code, GREEN is written as ITGGP, then how will OINK be written as in the same code?

In a certain code language, '+' represents 'x', '-' represents '+', 'x' represents '÷' and '÷' represents '-'. What is the answer to the following question?
550 x 22 - 24 + 3 = ?

If "*" denotes "added to", "&" denotes "divided by", "@" denotes "multiplied by" and "%" denotes "subtracted from", then 135 & 15 @ 10 % 3 * 6 = ?

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

9 ÷ 16 - 25 + 10 x 20 = ?

If 10$25 = 8, 12$25 = 10 then what is the value of 14$53 = ?

If "A" means "plus", "B" means "divide", "C" means "multiply" and "D" means "minus", then 187 B 17 C 4 A 7 D 17 = ?

In a certain code language, “FAINT” is written as “DYGLR”. How is “METRO” written in that code language?

In this question, some equations are solved on the basis of a certain system. On the same basis find out the correct answer from amongst the four alternatives for the unsolved equation.

7x6x8=678
8x9x7=987
6x5x7=567
5x4x6=?