(a) Decipher "GDZKXG", assuming an affine cipher [5,t] was used and that the cleartext is a name.

(b) Decipher "SXWGR", assuming an affine cipher [s,3] was used and that the cleartext is a name.

(c) Prove that a multiplication of the letters of an alphabet by a number t produces a cipher if and only if t and 26 are relatively prime.