A bank loaned out $15,000 to a college student. Part of this money was loaned at a rate of 6% per year, and the rest of the $15,000 was loaned at a rate of 13% per year. If the bank received $1390 in interest, how much was loaned at 6%?
A bank loaned out $15,000 to a college student. Part of this money was loaned at a rate of 6% per year, and the rest of the $15,000 was loaned at a rate of 13% per year. If the bank received $1390 in interest, how much was loaned at 6%?
how long was the loan active for?
assuming the interest collected was at the end of the first year:
let $\displaystyle x$ be the amoutn loaned at 6%. then $\displaystyle 15000 - x$ is the amount loaned at 13%
the interest on $\displaystyle x$ is: $\displaystyle 0.06x$
the interest on the rest is: $\displaystyle 0.13(15000 - x)$
the total interest is: 1390
thus, $\displaystyle 0.06x + 0.13(15000 - x) = 1390$
now solve for $\displaystyle x$