The sequence 15,30,45,60 look like 1,2,3, each term is 15 times as large. so, the formula is 15n, where n represents the position of a term in the sequence. check the first four terms

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