How do I math- please help like actually I beg you ;-;

What is the missing step in this proof ?

You are at a restaurant and owe $38 for your meal. you want to leave a 20% tip. how much will your tip be?

Peter applied to an accounting firm and a consulting firm. he knows that 30% of similarly qualified applicants receive job offers from the accounting firm, while only 20% of similarly qualified applicants receive job offers from the consulting firm. assume that receiving an offer from one firm is independent of receiving an offer from the other. what is the probability that both firms offer peter a job?