Question

Use the simple interest formula to determine the missing value. p=?, r=6%, t=9 months, i=81

Answer 1

P = 1800

Explanation:

The formula to calculate simple interest (I) is

I =
`(PRT)/(100)` ( note that time is in years ), thus

9 months =
`(9)/(12)` =
`(3)/(4)` = 0.75 years

Thus

81 =
`(P(6)(0.75))/(100)` ( multiply both sides by 100 )

8100 = 4.5P ( divide both sides by 4.5 )

P = 1800