The sum of three numbers is 78. the second number is two times greater than the first. the third number is 12 more than the find each number

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