If you would like to know the change in Debra's hours, you can calculate this using the following steps:
x% of 16 hours is 22 hours
x% * 16 = 22
x/100 * 16 = 22
x = 22 * 100 / 16
x = 137.5%
137.5% - 100% = 37.5%
22 hours - 16 hours = 6 hours
The correct result would be: an increase of 6 hours, and an increase of 37.5%.
The first one can be written as a fraction because it is a repeating decimal.
The second one can be written as a fraction because it is a repeating decimal.
The third one can not be written as a fraction since it is nether terminating nor repeating.
The last one can be written as a fraction since it is a terminating decimal.
The recursive formula that models the amount owed is
an = a(n-1) -75; a1 = 600.
This formula is for AFTER the first month of payment, this is why the first term is 700-100 = 600. This also means that n > 1.