The answer is 9/10
the denominator is on the bottom
We must take into account the following change of units:

Applying the change of units we have that the electric consumption for 1 year is given by:

Then, the total cost is given by:
Answer:
the cost of operating a 3.00-w electric clock for a year is:
$ 2.3652
The first one is 50 the second one is 1,500
7 books with a cost of 28$ then a 2$ charge which will put him right at 30