Chapter Twenty-Three — Word Problems
The Humongous Book of Algebra Problems
535
In this problem, the ingredients are 12- and 16-ounce containers of punch,
which contain 70% and 10% real juice, respectively. Convert the percentages
into decimals (70% = 0.7 and 10% = 0.1) and substitute the values into the
equation blueprint above. Let x represent the unknown value, the portion of the
final mixture that is real juice.
The mixture is approximately 35.71% fruit juice.
23.31 If a 5-pound bag of mixed nuts that is 45% peanuts by weight is combined with
a 12-pound bag of mixed nuts that is 40% peanuts by weight, what percentage
of the mixture is peanuts (by weight)? Report the answer as a percentage
rounded to the hundredths place.
Apply the blueprint for mixture and combination problems.
Multiply the first ingredient, a 5-pound bag, by 0.45 (its descriptive value 45%
expressed as a decimal). Multiply the second ingredient, a 12-pound bag, by its
descriptive value, 0.4. The mixture weighs 5 + 12 = 17 pounds; let x represent
the unknown descriptive value, the percentage of the mixture that is peanuts by
weight.
The mixture is approximately 41.47% peanuts by weight.
23.32 How much extra-virgin olive oil, containing 0.8% acidity, must be added to 4
gallons of olive oil with an acidity of 2.5% so that the mixture has an acidity of
2%? Report the answer in gallons, rounded to the hundredths place.
Apply the blueprint for mixture and combination problems.
To convert
from a decimal
to a percent, move
the decimal point two
places to the right.
Don’t round to the
hundredths place until
after you move the
decimal.