Calculate simple interest on a base of \(\$ 6,000\) for the following intervals and rates, using a 360-day year.

a 60 days at 12 percent b 60 days at 8 percent.

c 90 days at 9 percent.

d 60 days at 16 percent e 15 days at 16 percent

f 6 months at 9 percent.
g 5 months, 15 days at 12 percent.
h 4 months, 12 days at 9 percent.