math
posted by justme on .
I have some of the answers to this project but I need help with the last couple of answers.
Your next project will involve painting the walls and ceiling of your room. First find the surface area of each wall and the ceiling in square feet. NOTE: you need to CLEARLY identify which of your dimensions is the HEIGHT. Then add them together to find the surface area to be painted (#4). Assuming 1 gallon covers 350 square feet, find the amount of paint in gallons that you need to paint the walls and ceiling (#5). Then convert the number of gallons to liters (round to an accuracy of 0.1 liters) (#6).
You've decided you like the paint that is 3% color pigment. However, you've bought 7% paint on sale and can't take it back. How much 7% paint (#7) needs to be diluted with pure white paint (#8) to equal the amount of 3% paint (#5) you need?
The answer to #4 is 419 sqft.
The answer to #5 is 1.2 gallons.
The answer to #6 is 4.6 liters.
I can't figure out the formula needed to solve the rest of the problems.

.07(#7)+#8=.03*(#7+#8)
and of course, #7+#8=#5