Seventeen and nine hundred five thousandths in decimal form ​

Witch represents the inverse of the function f(x)=1/4x-12

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

Which one is the correct answer, and why?