P(a) = 1/4, p(b) = 2/3, p(a and b) = 1/6. are events a and b independent?

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