Please help me with his it needs to be in a fraction form

How long must $542 be invested at a rate of 7% to earn $303.52 in interest? in a easier way

Tom is the deli manager at a grocery store. he needs to schedule employee to staff the deli department for no more that 260 person-hours per week. tom has one part-time employee who works 20 person-hours per week. each full-time employee works 40 person-hours per week. write and inequality to determine n, the number of full-time employees tom may schedule, so that his employees work on more than 260 person-hours per week. graph the solution set to this inequality.

Asalesperson has january sales of $20,000(1,$20,000) and april sales of $80,000 (4,$80,000). what is the rate of change?