Idon't understand the steps how to solve it

Thomas hiked 6 miles on monday 10 miles on tuesday and 8 miles on wednesday. what is the mean value closesst to the mean number of miles over the tree day period?

Find the values of y: 3y^3(y^2+ 2/3y)=0

Anew shopping mall is gaining in popularity. every day since it opened, the number of shoppers is 5% more than the number of shoppers the day before. the total number of shoppers over the first 10 days is 1258 how many shoppers were on the first day?