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Mixture Problems

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 5-gallon 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?