Warm-up (get out a calculator)

If I have a 10mL solution that is 45% acid. How much acid is in the solution?

How much money did I invest in stocks that yielded a return of 5% if I earned $125?

What is a CD (certificate of deposit)? What is a bond? What is a stock?

Mixture/Investment Problems

Objectives: Write equations for mixture problems Solve the equations for valid solutions

Remember Back….

If the sum of two numbers is 25 and one is x what is the other number in terms of x?

If a mixture is formed by combining x mL of acid with 300mL of water what is the total amount of mixture?

Problem 1

Note: %Interest x Principle = Income A securities broker advised a client to invest

a total of $21,000 split between bonds paying 12% and certificates of deposits paying 5.25%. The annual income from the investments is $2250. How much was invested in each type of investment?

Problem 2

A grocer makes a natural cereal by mixing oat cereal costing $2 per kilogram with dries fruits costing $9 per kilogram. How many kilograms of each are needed to make 60kg of cereal costing $3.75 per kilogram?

Problem 3

How many liters of a 6% acid solution must be added to 20 L of a 24% acid solution to make a solution that is 8% acid?

20L of 24%

x liters of 6%

Mixture of 8% acid

Problem 4

How much water must be added to a 80% salt solution in order to make 10 ounces of 55% salt.

HINT: make sure all percents are in the same units

Answers Page 1 & 2

Page 1 $1600 stocks,

$4400 bonds $1600 cd’s,

$2400 bonds $1200 bonds,

$600 stocks $10,000 bonds,

$12,000 stocks

Page 2

1. 8kg of $4.00 12kg of $5.00

2. 4.5g of water should be added

3. 5g of water should be added