Clueless - Math story problem?

Question

This one I'm totally clueless about. I don't even know where to start. "The labor cost for installing ceramic floor tile in a rectangular room varies jointly with the length and width. For a room that is 8 feet by 10 feet the cost is $400. For a room that is 9 feet by 12 feet the cost is $540. What is the cost for a room that is 11 feet by 14 feet."

Answer 1

find the rate of installing = cost/area of room
=$400/(8*10)=$5per square feet
so, cost for new room=$5*11*14=$770

Answer 2

Area of a rectangle = length x width

As the cost varies jointly with length and width, then it varies jointly with the area.
Or the cost is proportional with the area.

Thus, Cost = k x area, where k is a constant.

From the 1st equation,
400 = 8 x 10 x k,
solving for k = 400/80 = 5

Now check with the 2nd equation,
9 x 12 x 5 = 540 (correct).

Now, cost of room 11 x 14 is 11 x 14 x 5 = $770

Answer 3

Use Square feet

Square feet is calculated by the width times the length of the room.

An 8x10 room is 80 square feet. At $400, that is $5/SF installation cost.

A 9x12 room is 108 square feet. At $540, that is also $5/SF installation cost (see a pattern here?)

A room that is 11x14 feet is 154 square feet. To calculate the cost, multiply the square footage of the room, times the installation cost (154 SF x $5/SF)

See if you can figure out the answer yourself, but I will provide it below as a check.

Dont Peek!

Ok, here it comes.....

The answer is $770

Answer 4

Multiply 8 times 10 to get the square footage

8 x 10 =80 square feet

divide 400 by 80 to get the cost per square foot

400 / 80 = 5

The cost of labor for installing ceramic floor tils is $ 5.00 per square foor.

Multiply 11 times 14 to get the square footage..

11 x 14 = 154 square feet

Multiply 154 times 5 to get the cost for installating ceramic floor tiles

154 x 5 = 770

The cost for installing ceramic floor tiles is $ 770.00

- - - - - - - - - -s-

Answer 5

First find square feet by multiplying the dimensions for each room.

80 sq ft costs $400
80/400 = 1/5 so 1 sq ft costs $5

108 sq ft costs $540
108 / 540 = 1/5

The 11x14 room has 154 sq ft.

154/x = 1/5
5(154) = x
$770 = x

Answer 6

its very simple: Use Algebra ( x is the rate of pay in Dollars($))

we know that 8x by 10x = 400 therefore 80x = 400 so
x = 400/80 = 5

Check with second equation
we know that 9x by 12x = 540 therfore 108x = 540 so
x = 540/108 = 5

that is what we want

so we just multiply 14 by 11 = 154x
then multiply 154 by 5 = $770
Voila!!!

Answer 7

8x10=80 sq ft -->$400
9x12=108sq ft -->$540

means 1 square feet cost is $5
(I got it from 400:5 or 540: 108)

11x14=154 sq ft
154 x$5 = $ 770

Answer 8

i don't recognize a thank you to do it yet i could start up via questioning of all the aspects of 14. 7+7, 8+6, and 9+5. because of the fact it may't be extra desirable than one hundred%, top? can't be seventy seven because of the fact which you may not turn those numbers around. Now turn the numbers around and subtract the extra desirable from the smaller. 86-68=18, so it is not 86. ninety 5-fifty 9=36. this could be a tough issue, desire it truly is the only one you have!

Answer 9

The price is a function of the area.

8 ft * 10 ft = 80 sq ft
That also equals $400, so....
$400/80 sq ft = $5.00/sq ft

9 ft * 12 ft = 108 sq ft
and at $5.00/sq ft, that equals $540.

11 ft * 14 ft = 154 sq ft

154 sq ft * $5.00/sq ft = $770

Answer 10

FIRST FIND HOW MUCH PER SQUARE FOOT BY MUTLIPLING TOGETHER 8*10=80SQFT
80SQFT COST $400.00
FIND HOW MUCH PER SQUARE FOOT BY DIVIDING
400/80=$5.00 PER SQUARE FOOT
IF YOU HAVE 11x14FT=154SQFT
154SQFTX$5.00=$770.00
CHECK WITH OTHER MEASURMENT TO MAKE SURE
9FTX12FT=108SQFT
108SQFTX$5.00=$540.00