You put $600 into an account. The account earns 5% simple interest per year. What is the balance after 4 years? (THERE ARE OPTIONS)
A. $120
B. $720
C. $1800
D. $12,600

To determine how many students were at Marita's school last year with the provided information, the equation would be 1,350 = 90%(x). Another way to write it is 0.9x = 1,350. Divide both sides by 0.9, and the answer is 1,500. There were 1,500 students at the school last year.