1. Is set containment ⊂ an equivalence relation?
2. Decrypt the message q kiv pih kpmmhjczomz, which was encrypted using a cipher that shifted by eight letters.
3. Decrypt the message q kiv pih kpmmhjczomz, which was encrypted using a cipher that shifted by eight letters.
4. Decrypt the message dtrn utzaknr dbbv utzaknr T lbt'b zoam po gabbd hvlwoec, which was encrypted using a Vigen`ere cipher with key word lady. Which type of Vigen`ere cipher was used?