Answer:
P = 1800
Step-by-step explanation:
The formula to calculate simple interest (I) is
I = [tex]\frac{PRT}{100}[/tex] ( note that time is in years ), thus
9 months = [tex]\frac{9}{12}[/tex] = [tex]\frac{3}{4}[/tex] = 0.75 years
Thus
81 = [tex]\frac{P(6)(0.75)}{100}[/tex] ( multiply both sides by 100 )
8100 = 4.5P ( divide both sides by 4.5 )
P = 1800
