Coding and Decoding Questions

If "A" denotes "multiplied by", "B" denotes "subtracted from", "C" denotes "added to" and "D" denotes "divided by", then

7 B 17 C 88 D 11 A 6 = ?

If 3 @ 3 * 3 = 3 and 48 @ 4 * 3 = 36, then 91 @ 13 * 2 = ?

In a certain code language, "MOTHER" is written as "NPUGDQ". How is "ORANGE" written in that code language ?

If 5 * 3 = 19 and 8 * 5 = 49, then what should 6 * 4 be?

If 6 @ 4 @ 7 = 101 and 2 @ 5 @ 11 = 150, then what is the value of A in A @ 8 @ 9 = 289?

In a certain code language, "LIAR" is written as "5782" and "RANGE" is written as "28641". How is "ARRANGE" written in that code language?

If 5$125 = 25, 12$48 = 4 then what is the value of 4$24 = ?

In a certain language "BROTHER" is written as "CSPUIFS". How is "SISTER" written in that code language?