Real-Life Math
You may think that painting a house is just about picking the right
color, but it's not. It involves people skills, technical know-how --
and more math than you might expect!
Joe Wolfe owns his own house painting
business.
"I use math for pretty much everything," he says, "from wages,
to determining how much paint I'll need, to figuring out paint-water
ratios and pricing a job. Every aspect of painting requires some
math."
Painters need more than a keen eye and a steady hand to be successful.
They also have to be able to bid for potential jobs. If a bid is too high,
they might lose the job to a competitor. If it is too low, they won't
make any money.
You've just been called out to give an estimate
for a paint job. It's a big house and the owner wants it ALL painted.
She informs you that she'd like a written bid for the job -- and tells
you she's also getting bids from other painters in town.
The house
has 5 rooms and a hallway. The kitchen is 25 feet by 20 feet. There are 3
bedrooms. Bedroom A is 30 feet by 27 feet. Bedroom B is 15 feet by 15 feet
and bedroom C is 12 feet by 10 feet. The living area is a colossal 30 feet
by 35 feet. The hall is 20 feet by 4 feet.
You know that 1 gallon of
paint will cover 100 square feet (assuming the rooms have 9-foot ceilings).
Paint costs $18 per gallon, plus 7 percent tax.
Because it is such
a big job, you may need help. An assistant will cost $7 per hour and you estimate
that you'll need 2 assistants for about 80 hours each. You figure that
you'll be working on the house for 100 hours -- and generally you make
$10 per hour. Your usual price is $1.25 per square foot. You estimate that
supplies will cost $200.
Write up your first estimate using $1.25 per
square foot. How much money will you make? Will it cover everything? Do you
have room to bring the price per square foot down? What is your break-even
price per square foot?