My homework question is to answer this equation - mary jones works at java joes, she gets paid $10.55 every hour. she works there for 4 hours a day. how much money does she have after 3 days?

Serena is making an experiment. for that, she needs 20 grams of a 52% solution of salt. she has two large bottles of salt water: one with 40% and the other with 70% of salt in them. how much of each must she use to make the solution she needs? i am in need of