What is 3,333 divided by 3?
a.1,112
b.1,113
c.1,111
d.none of the above

Let be the number of liters of the 10% solution she needs to use. She'd end up with a 6% solution with a volume of liters. The starting solution contains 0.04*9 = 0.36 liter of salt. Each liter of the 10% solution contributes 0.1 liter of salt, so that

Solve for :

so Mayra needs to add 4.5 liters of the 10% solution.