a mother wants to invest 7000 for her son's future education.she invest in two account: a money market fund that pays 4% and a certificate of deposit that pays 7%. if the total interest earned after one year is $420, how much money was invested in each account?
this is just a typical mixture problem. If $x is at 4%, then the rest (7000-x) is at 7%. So, adding up the interest, you have
.04x + .07(7000-x) = 420posted by Steve