So I solve this by my favorite heuristics method (by some people also called by trial & error). We know that $5,000 is invested in bonds that pay 6% resulting in $300 of income. That leaves us $19,000 to invest which must yield $1,200. If that sum were invested equally in bonds and mutual funds that sum of $12,000 at an average 6.5% would yield $1,235. That is $35 more that must come from the lower yielding money market account, which pays 1.5% less. Then we divide the $35 by 0.05 = $2,333.33. Next we take this sum off of $19,000 and get $16,666.67, half of which is in mutual fund and the other half plus $5,000 is in bonds. That gets us to this scenario:
M/M: $2,333.33 x 0.05 = $116.67
M/F: $8,333.33 x 0.07 = $583.33
Bonds: $13,333.33 x 0.06 = $800
Total interest received: $1,500.00
Problem solved with shear logic.
claire inherited $24000 and invested part of it in a money market account, part in municipal bonds, and part in a mutual fund. After one year, she received a total of $1500 in simple interest from three investments. The money market paid 5% annually, the bonds paid 6% annually, and the mutually fund paid 7% annually. There was $5000 more invested in the bonds than the mutual funds. Find the amount Claire invested in each category.
