Help. It’s ez but idk how to do it

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

On friday, there were x students at the baseball game. on monday, there were half as many students at the game as there were on friday. on wednesday, there were 32 fewer students at the game as there were on friday. which expression could represent the total number of tickets sold for all 3 games?

Susan is paying $0.30 per $100 on her $483,000 home in homeowners insurance annually. if her annual homeowners insurance premium is divided into twelve equal monthly installments to be included on each of her monthly mortgage payments of $2,128.00, what is her total monthly payment?