If a fire truck is pumping water at a rate of 200 l/min, how long will it take to put out a fire in a room with a floor area of 140m squared

Step-by-step explanation:

step 1

Find the minimum volume of water needed to fight a room with a floor area of 140 m^2

see the attached table to better understand the problem

we know that

A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form or

Let

x ----> the floor area in square feet

y ---> minimum volume of water in liters

In this problem the relationship between the variables x and y represent a direct variation

Find the constant of proportionality k

Looking at the table

For x=25, y=39

---->

The equation is

For x=140 m^2

substitute and solve for y

step 2

How long will it take to put out a fire in a room with a floor area of 140 m^2

we know that

The fire truck is pumping water at a rate of 200 L/min

The minimum volume of water needed is 218.4 L

so

Divide the minimum volume of water needed by the rate

Well, it's the perimeter, so...40.

You just calculate the perimeter of a rectangle with the lenght of 12 and width of 8, by the formula

or you can factor it out.