Help with 5 or 6 or both please!

Which of the following is the explicit rule for a geometric sequence defined a recursive formula of a -5a for which the first term is 23?

Astore is having a sale in which all items are reduced by 20 percent. including tax, jennifer paid $21 for a pair of shorts. if the sales tax is 5 percent, what was the original price of the shorts

Me : julio wears a blue shirt every 3 days. larry wears a blue shirt every 4 days. on april 11, both julio and larry wore a blue shirt. what is the next date that they will both wear a blue shirt?