Coding and Decoding Questions

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

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

15 - 5 + 25 ÷ 10 = ?

If 8%5 = 30, 9%2 = 70 and 1%4 = -30, then find the value of 2%5 = ?

If "S" denotes "multiplied by", "P" denotes "subtracted from", "R" denotes "added to" and "Q" denotes "divided by", then 14641 Q 121 P 100 S 2 R 100 = ?

In a certain code, 592 means 'grapes are sweet', 374 means 'I like oranges' and 267 means 'oranges are sour'. Which digit represents sour?

If 19 $ 7 = 312 and 23 $ 9 = 448, then 31 $ 11 = ?

If x stands for - , + means x , ÷ means + and - means ÷ , then what is the value of the given expression?

175 - 25 ÷ 5 + 2 x 3 + 10 = ?

In a certain code language, "FIRST" is written as "@#$!?" and "EYE" is written as "^*^". How is "TYRE" written in that code language?