PLZ ANSWER FAST Mr. Miller took a poll of which students in his class have gone to a water park. If 7/9 of his class have visited a water park for a total of 21 students, then how many total students are in Mr. Miller's class?

Mrs. avila is buying a wallpaper border to go on all of her kitchen walls. she wants to buy 5 extra feet of wallpaper border than she needs to be sure she has enough. she buys 55.5 feet of the border. the store owner selling the border uses the width of mrs. avila's kitchen to determine that the length of her kitchen must be 14.5 feet.