# During the first month after the opening of a new shopping home, sales were $72 million. Each subsequent month, sales declined by the same fraction. If the sales during the third month after the opening totaled $18 million, what is that fraction?

##### 3 Answers

I need some clarification.

#### Explanation:

1st month

3rd month

I assume that you are saying that every month, the sales drop in this manner:

1st month is $72 million,

(Letting fraction =

2nd month is $

So 3rd month is $

If so, please give me the thumbs up to go ahead..

Because it can also mean a fraction the original $72 million was removed in the 2nd month.

#### Explanation:

If we model this on an exponential function:

So

Testing this:

looking at $18 M. after 3 months.

We would expect after 6 months the amount to be:

And:

#### Explanation:

I'm reading the question this way - We have sales in Month 1 of $72M, month 3 of $18M, and an equal fraction decline from months 1 to 2 and 2 to 3. What's that fraction?

The first thing I'd do is to look at the fraction decline from 72 to 18:

Since this represents the total decline over 2 months, by observation we can see the fraction is

Testing this, we should see sales declining by

Month 1:

Month 2:

Month 3: