Answer:
see below
Step-by-step explanation:

Think of the above as:
* 
=
* 
=
* 
=
* 
= 
= 
Can flip it around to be...

If you multiply them all you get 3.0519273e+15 as your answer.
Answer: 8 subsets----------------------------------------------------------------------
----------------------------------------------------------------------
There are n = 3 elements in the given set, so there are 2^n = 2^3 = 2*2*2 = 8 subsets. Those 8 subsets are listed below
{a,b,c}
{a,b}, {a,c}, {b, c}
{a}, {b}, {c}
{ }
The first row is the original set. Any set is a subset of itself.
The second row represents subsets with exactly 2 elements.
The third row represents subsets with exactly 1 element
The fourth row is the empty set which can be written as
<u><em>(The Explanation):</em></u> What we are given is that the car drives 45 miles each hour. Furthermore, you need to multiply the amount of hours desired to the miles to get a total mile.
<u><em>(Step-By-Step Instructions):</em></u>
<em>45(4) and 45(20) </em> Multiply
<u><em>The Answers:</em></u> 4 hours = 180 miles / 20 hours = 900 miles