Word problem... Question below

Question

Angela needs 12 quarts of 50% antifreeze solution in her SUVs radiator. She plans to obtain this by mixing some pure antifreeze with an amount of a 40% antifreeze solution. How many quarts of EACH solution must she use?

 

Need two equations

Answer 1

12 quarts of a 50% antifreeze solution means you want 6 quarts of antifreeze

x=# of quarts of pure antifreeze

x+(12-x)40%=6 (50% of 12=6)

x+4.8-0.4x=6

0.6x+4.8=6

0.6x=6-4.8

0.6x=1.2

6x=12

x=2 quarts of pure antifreeze

12-2=10 quarts of 40% antifreeze (40% of 10=4 quarts antifreeze + the 2 quarts of antifreeze equals 6 quarts)