Colin just graduated from college with a degree in engineering. he decided to create a personal budget to him pay all of his bills and still save money for retirement. his first monthly paycheck, after taxes, was $3,900. he had the following expenses. fixed expenses (rent and monthly bills) were $2,535. he spent $507 for food. entertainment cost him $390. the remainder of his paycheck colin placed in a savings account for retirement. what percent of his paycheck did he save for retirement?
a. 12%
b. 22%
c. 17%
d. 7%