For each of the problems below, do the following:
(a) Identify the unknown quantity (quantities)
(b) Define a variable (or variables) to represent the unknown
(c) Write an equation that describes the information given in the statement of the problem
(d) Solve the equation and answer the problem.
3. You have a 4 litre jug of 3.5% milk (milk that contains 3.5% fat). How much skim milk (0% fat) do you need to add to it to obtain milk which will have 2% fat?
4. 280 people joined the community band. Some intended to play a woodwind instrument, some a brass instrument, and the others percussion. If 2 times as many people were planning to play a woodwind instrument as a brass instrument, and if 80 fewer were going to play percussion than a brass instrument, how many people were planning to play each type of instrument?

(3) 3 liters   (4) Woodwind = 180, Brass = 90, Percussion = 10

Step-by-step explanation:

3) Set up a table. Multiply across and add down to create the equation.

                    x             = 3        ---> subtracted 4 from both sides

4)

Woodwind: 2x

Brass:            x

Percussion:   x - 80

      TOTAL:  4x - 80 = 280

                     4x         = 360      ----> added 80 to both sides

                       x         =  90       ---> divided 4 from both sides

Woodwind: 2x ---> 2(90) = 180

Brass:           x  --->     90

Percussion:  x - 80 ---> 90 - 80 = 10

answer: the value should be used for i in the formula of calculation the monthly payment , the interest rate per period is 0.85.

step-by-step explanation:

the given rate of interest i= 85%

in calculating the monthly payment for a loan with an interest rate compounded monthly, the value of the interest rate per period we use in the formula must be in decimal form.

to convert it in decimal, we divide it by 100, we get

hence, the value should be used for i in the formula of calculation the monthly payment , the interest rate per period is 0.85.

1. d.90

2. e. none of these (80)

3. a. 0

4. b. 6

5. e. none of these (10)

6. a. 5