Solve Mixture Word Problems
These word problems need to be solved by writing two equations with two
unknowns. The first equation will involve just the variables and the total amount.
The second equation will contain the values, EVERYWHERE.
Skeleton:
x + y = total amount
($) x + ($) y = ($) total amount
A wild birdseed mix is made by combining 100 lb
of millet seed costing $.50 per pound with
sunflower seeds costing $1.20 per pound. How
many pounds of sunflower seeds are needed to
make a mixture that costs $.71 per pound?
A lumber company combined oak wood chips that
cost $3.00 per pound with pine wood chips that
cost $2.50 per pound. How many pounds of each
were used to make a 50-pound mixture that cost
$2.85 per pound?
Let
Let
Amount
Amount
w/Value
total
Millet
100
sunflower
S
total
100 + s
Amount
.50(100)
1.20(s)
.71(100+s)
Amount
w/Value
– ( Duh! )
100 + s = 100 + s
.50(100) + 1.20(s) = .71(100 + s)
50 + 1.2s = 71 + .71s
- .71s
- .71s
50 + .49s = 71
- 50
- 50
.49s = 21
(1/.49).49s = 21(1/.49)
You need about 51.22 pounds of sunflower seeds.
Find the cost per ounce of a gold alloy made
from 25 oz of pure gold that cost $420 per
ounce and 45 oz of an alloy that costs $350 per
ounce.
Pure
Alloy
How many liters of blue dye that costs $1.60 per
liter must be mixed with 18 L of another dye that
cost $2.50 per liter to make a mixture that cost
$1.90 per liter?
Expensive
total
Amount
Amount
Amount
w/Value
Amount
w/Value
Cheap
total
These word problems need to be solved by writing two equations with two
unknowns. The first equation will involve just the variables and the total amount.
The second equation will contain the values, EVERYWHERE.
Skeleton:
x + y = total amount
(%) x + (%) y = (%) total amount
How many ounces of pure bran flakes must be
added to 50 oz of cereal that is 20% bran flakes
to produce a mixture that is 50% bran flakes?
Pure
Weak
How many pounds of a chicken feed that is 50%
corn must be mixed with 400 lb of a feed that is 80%
corn to make a chicken feed that is 60% corn?
Weak corn
total
Amount
Amount
Amount
w/Value
Amount
w/Value
Strong corn
total
One hundred ounces of juice that is 30% tomato
juice are added to 200 ounces of a vegetable
juice that is 16% tomato juice. What is the
percent concentration of tomato juice in the
resulting mixture?
Strong
Weak
A chemist wants to make 50 ml of a 12% salt
solution by mixing a 20% salt solution and
water. How many milliliters of each should
the chemist use?
total
Salt
Amount
Amount
Amount
w/Value
Amount
w/Value
Water
total