A chemist needs to mix 6 liters of 50% acid solution with some 20% solution to obtain a 38% solution. how much of the 20% solution should the chemist use.

Question

A chemist needs to mix 6 liters of 50% acid solution with some 20% solution to obtain a 38% solution. how much of the 20% solution should the chemist use.

Answer 1

50%(6)+20%(x)=38%(6+x)

0.5(6)+0.2(x)=0.38(6+x)

3+0.2x=2.28+0.38x

3.00-2.28=0.38x-0.20x

0.72=0.18x

72=18x

x=72/18

x=4 liters of the 20% solution is needed