# The Sparkling House Cleaning Company has cleaned 28 houses this week. If this number repesents 40% of the total number of houses the company is contracted to clean, how many total houses will the company clean by the end of the week?

May 16, 2017

$42$ houses left, so $70$ will be cleaned in total

#### Explanation:

If the company completed $28$ houses so far (this is 40% of the total number of houses), then they have to clean $70$ houses within one week.

It means $x = 100 \cdot \frac{28}{40}$

where, $x$ is the total houses must be cleaned per week.

Then you can get $x = 70$.

It means they have to clean $70 - 28 = 42$ more houses by the end of week.

Your answer is $70$ houses.

May 16, 2017

$70$ houses in total for the week.

#### Explanation:

This can be answered by using direct proportion.
Any percent question can be done this way.

We know that $28$ houses represent 40%

We want to know the total number of houses - the 100%

Write them as a proportion:

x/100 = 28/40" "(larr"houses")/(larr "percent")

$x = \frac{28 \times 100}{40}$

$x = 70$ houses

You could also write the proportion like this:

$\text{percents "40/100 = 28/x" houses}$ which gives the same result:

$x = 70$ houses