please help ill give medals and fans

The simple interest formula I=prt gives the interest earned on an investment of p dollars at interest rate r for a time of t years. How much does Marisol need to invest at a rate of 9% in order to earn $270 interest in 3 years?

Question

please help ill give medals and fans

The simple interest formula  I=prt  gives the interest earned on an investment of  p  dollars at interest rate  r for a time of  t  years. How much does Marisol need to invest at a rate of 9% in order to earn $270 interest in 3 years?

mokeira · Answer

$$P=Interest \times rate \times time$$
Rate=9%
Interest=$270
Time=2years
$$270=P \times \frac{ 9 }{100 } \times 3$$
$$270=\frac{ 27P }{100 }$$
27000=27P
1000=P

xapproachesinfinity · Answer

it is the other way around
i=prt
looking for p

xapproachesinfinity · Answer

well the answer was right
just the first line needed to be corrected

mokeira · Answer

I have substituted...my method is correct

xapproachesinfinity · Answer

no the first statement is wrong!
what kind of substitution are talking about

mokeira · Answer

lol..i see what you mean..

xapproachesinfinity · Answer

Right! ^_^