A person invested $8000 for 1 year, part at 7%, part at 9%, and the
remainder at 13%. The total annual income from these investments was
$858. The amount of money invested at 13% was $400 more than the
amounts invested at 7% and 9% combined. Find the amount invested at
each rate.
The person invested $ at 7%, $ at 9% and $ at 13%