Section 2-7: Mixture Problems
1) Coin/money problems, stamp problems.
2) Mixture problems or blending problems involving coffee, nuts, minerals, acid, etc.
a. Solved by the premise: ( number of units ) ( value of 1 unit ) = total value
3) Mixture problems involving percent.
a. Solved by the premise: ( total amount ) ( % of pure substance ) = amount of pure substance
Section 2-7 Statement Problem Examples
1) Ed has $ 7.80 in nickels and half–dollars. If he
has three times as many nickels as half–dollars,
how many of each does he have?
2) Kirk bought some 18¢ stamps and some 22¢
stamps. He bought 35 stamps in all and paid
$ 7.10 for them. How many stamps of each kind
did he buy?
3) Tickets to the school play cost $ 3 in advance
and $ 4 at the door. In all, 684 tickets were sold
for a total of $ 2,457. How many tickets were
sold at the door?
4) On a test each question in Part A was worth
4 points and each question in Part B was worth
6 points. George answered 15 questions correctly
and had a point total of 76. How many did he
answer correctly in each part of the test?
Section 2-7: Mixture Problems – Page 2
5) How many liters of water must be added to 20 L
of a 24% acid solution to make a solution that is
8% acid?
6) If 800 mL of a juice drink is 15% grape juice, how
much grape juice should be added to make a drink
that is 20% grape juice?
7) How many kilograms of water must be
evaporated from 12 kg of a 5% salt solution to
produce a solution that is 30% salt?
8) The students in a chemistry class have 75 mL of a
pure acid which must be diluted to a solution that
is 10% acid. How many milliliters of water should
they add?