Set up a proportion:

The numerator represents fluid ounces of milk, and the denominator represents milligrams of calcium.
Simplify the first fraction to make multiplication easier:


Cross multiply the fractions:


Divide both sides by 135 to get x by itself:

2.1 fluid ounces of milk provide 72.5 milligrams of calcium.
Showing the relationships among concepts.
Answer: 2.815 kilograms
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Work Shown:
1 layer = 0.5 kg
5 layers = 5*(0.5 kg) = 2.5 kg
icing = 15 g = 15/1000 = 0.015 kg
1 candle = 100 g = 100/1000 = 0.1 kg
3 candles = 3*(0.1 kg) = 0.3 kg
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The five layers combine to 2.5 kg. On top of that we have 0.015 kg of icing, and then finally the three candles add 0.3 kg more weight.
The total weight is therefore: 2.5+0.015+0.3 = 2.815 kilograms
X-5.1 = -7.6
+5.1 +5.1
X= -2.5
20%. total= 5 => total= 25