The amount of simple interest earned, n, varies jointly with the rate of interest, r, and the number of years, t. The simple interest earned is $225 when the rate of interest is 4. 5% for 4 years.

Zachary has been trying to work on an essay for almost three hours, be he can't seem to focus for more than 15 or 20 minutes at a time. what should he do so that the quality of his work doesnt suffer because of poor concentration and lack of energy