Question

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

Answer 1

Answer:

$1.09\ min$

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 $y/x=k$ or $y=kx$

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

$k=y/x$ ---->$k=\frac{39}{25}=1.56$

The equation is

$y=1.56x$

For x=140 m^2

substitute and solve for y

$y=1.56(140)$

$y=218.4\ L$

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

$218.4/200= 1.092\ min$