Answer:
8.46 gallons needed to be replaced
Step-by-step explanation:
Let x be the alcohol amount that replaced
-Original has concentration of 15% multiply by the amount of 10 ,which is equal to (0.15×10).
-Removed has concentration of 15% multiply by the amount of x ,which is equal to (0.15 × X).
-Added has concentration of 80% multiply by the amount of X ,which is equal to (0.8× X).
-Solution has concentration of 70% multiply by the amount of 10 ,which is equal to (0.70×10).
So that, the equation will be:
Solution=Original + added - removed
7=1.5+0.8x-0.15x
7-1.5=0.65x
0.65x=55
x=55/0.65
x=8.46
8.46 gallons needed to be replaced.
