10) Last year the enrollment in a kindergarten was 150 pupils. This year the enrollment is 180 pupils. What was the precent of the increase in enrollment?

a. 5 1/8  b. 10  c. none of these  d. 20%  e. $.45  f. 16 3/4%  g. $2,200  h. 1,600 miles  i. 79  j. -9