Someone explain how this is answer C? Big points!

Icould really use some with this question.

Ibeg you to me 20. a reaction produces 4.93 l of oxygen, but was supposed to produce 1 mol of oxygen. what is the percent yield?

Derek purchased a new gym membership. it costs him seven dollars a month plus two dollars for every time that he visits the gym. he wants to spend less than 25 dollars a month to visit the gym. write an inequality that models the situation using the variable v for the number of visits per month. also find the maximum number of visits he can make to the gym and still keep his cost below 25 dollars a month.