 Mixture Problems,
a selection of answers from the Dr. Math archives:
 Alcohol Solutions
 How many liters of a 14 percent alcohol solution must
be mixed with 20 liters of a 50 percent alcohol solution
to get a 20 percent alcohol solution?
 Blending Seed
 How much of $0.65/lb seed does a dealer need to combine
with 200 lbs of $0.45/lb seed to make a $0.55/lb blend?
 Changing the Concentration
of a Solution
 A chemist has 6 liters of a 25% alcohol solution. How much
alcohol must he add so that the resulting solution contains
50% alcohol?
 Coffee or Tea?
 Is there more coffee in the tea, or more tea in the coffee,
or are they the same?
 How Much Water Evaporated?
 A substance is 99% water. Some water evaporates, leaving a substance
that is 98% water. How much of the water evaporated?
 Mixing Milk and Butterfat
 Milk that has 5% butterfat is mixed with milk that has
2% butterfat. How much of each is needed to obtain
60 gallons of milk that has 3% butterfat?
 Mixing Peanuts and Cashews
 Peanuts sell for $3.00 per pound. Cashews sell for
$6.00 per pound. How many pounds of cashews should be
mixed with 12 pounds of peanuts to obtain a mixture
that sells for $4.20 per pound?
 Mixture Problem
 How much pure antifreeze should be added to 3 gallons
of a 30 percent antifreeze solution to get 65 percent
antifreeze?
 Percentage of Alcohol in a Solution
 How do I find the percentage of alcohol in 30 liters of
a solution that is mixed with 5 liters of a 90% alcohol
solution?
 Raising the Antifreeze Ratio
 A 5gallon radiator containing a mixture of water and
antifreeze is supposed to contain a 50% antifreeze solution...
 10% Sodium + 30% Sodium
 A group of chemists are conducting an experiment to produce a new liquid
material. One chemical contains 15% sodium (Na) and the other chemical
contains 30% sodium (Na). Once they mix the two samples the resulting
chemical contains 22% sodium (Na). How many milliliters (ml) of each
sample must be mixed to obtain 600 ml of the new chemical?
 The Ratio of Water to Wine
 A cask is filled with 45 gallons of wine. Nine gallons
are removed and the cask is refilled with water. The nine
gallons of the mixture are removed and the cask is again
refilled with water. What is the ratio of water to wine
in the final mixture?
 Silver Alloy
 Sterling Silver is 92.5% pure silver. How many grams of
pure silver and sterling silver must be mixed to obtain
100g of a 94% Silver alloy?
 Tea Blend: Price of Inferior Tea
 6 kg of inferior quality tea are mixed with 3 kg of high
quality tea. What is the price of the inferior tea?
 Weighted Averages
 An advertisement for an orange drink claims that the drink
contains 10% orange juice. How much pure orange juice
would have to be added to 5 quarts of the drink to obtain
a mixture containing 40% orange juice?
