Target concentration = 20%.
Ratio of 12% and 30% alcohols needed
30-20 : 20-12 = 10:8 = 5:4
Volume of 12% = 72 mL * (5/(5+4)) = 40 mL
Volume of 30% = 72 mL *(4/(5+4)) = 32 mL
Total = 40+32 = 72 mL of 20%
Hi!
10 / 5 = 2
12 / 6 = 2
That means Peter spent $2 on each bottle.
2 × 7 = 14
Peter will pay C) $14.00 for 7 juice bottles.
I hope this helps you out!
How to solve your problem
6= 1- b
Solve
1. Rearrange terms
6= 1-b
6=-b+1
2. Subtract 1 from both sides of the equation
6= -b+1
6-1=-b+1-1
3. Simplify
Subtract the numbers
5=-b
Soulution
b=-5