Consider the suggested option: 1) if in 20 gr. of 50% solution given, then pure salt in this mix is 0.5*20=10 gr., and pure water is 0.5*20=10 gr. 2) after Maya added 5 gr. pure salt is 10+5=15 gr. Total mass of mix is 15(pure salt)+10(pure water)=25 gr. 3) new solution is 15/25=0.6 or 60%. Answer: 25 gr. of 60% salt solution.
