From the table, for every 6 containers of water, you need 8 containers of red dye. So, for every one container of red dye you need 0.75 containers of water (6/8). Then, multiply that by 100 (since you wanted to know water necessary for 100 containers of red dye). For 100 containers of red dye, you would need 75 containers of water.
A gram, because a milligram is one thousandth of a gram.
Set it up as an equation: 12 + 6x = 47
(x is the reduced fee)
12 + 6x = 47
12 - 12 + 6x = 47 - 12
6x = 35
x = 35/6
x = 5.83 repeating (only the 3 is repeating)
