I need help pls pls thank you so much! :)

How long must $542 be invested at a rate of 7% to earn $303.52 in interest? in a easier way

If g^-1(x) is the inverse of g (x) which statement must be true

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