



 
Hi Jean, If the annual interest rate is 12% and you invested $\$400$ then the income at the end of the year would be
You don't know the amount invested so call it $P$. You know the income at the end of the year is $\$30$ so the expression in this case is
Solve for $P$. Penny  


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences. 