Question 392016
Let x = the required amount of 7% nitrogen(?) mixture, then (200-x) = the required amount of 8% nitrogen mixture. The sum of these two amounts are to equal 200 units of 7.7% nitrogen solution. The equation, after converting the percentages to their decimal eqivalents is:
{{{x(0.07)+(200-x)(0.08) = 200(0.077)}}} Solve for x.
{{{0.07x+16-0.08x = 15.4}}} Simplify.
{{{-0.01x+16 = 15.4}}} Subtract 16.
{{{-0.01x = -0.6}}} Divide by -0.01
{{{x = 60}}}
The company will need to mix 60 units of the 7% nitrogen solution with 140 (200-60) units of the 8% nitrogen solution to obtain 200 units of 7.7 nitrogen mixture.