2/3y + 1/6y = Please help me, I am unsure about this one. I just need a grasp on where to start.

Select the margin of error that corresponds to the sample mean that corresponds to each population: a population mean of 25, a standard deviation of 2.5, and margin of error of 5%

Ametal rod is 2/5 meters long. it will be cut into pieces that are each 1/30 meters long. how many pieces will be made from the rod?

On friday, there were x students at the baseball game. on monday, there were half as many students at the game as there were on friday. on wednesday, there were 32 fewer students at the game as there were on friday. which expression could represent the total number of tickets sold for all 3 games?