73,098 views
5 votes
5 votes
Maricopa’s Success scholarship fund received a gift of $195000. The money is invested in stocks, bonds, and CDs. CDs pay 2.25% interest, bonds pay 4.9% interest, and stocks pay 7.5% interest. Maricopa Success invests $65000 more in bonds than in CDs. If the annual income from the investments is $10972.5, how much was invested in each account

User Sphinx
by
3.1k points

1 Answer

22 votes
22 votes

Solution

- Let the amount invested in stocks, bonds, and CDs be s, b, and c.

- The total fund is 195000. This means:


s+b+c=195000\text{ \lparen Equation 1\rparen}

- We are also told that the interests from the investments are


\begin{gathered} 2.25\%\text{ of c}=(2.25)/(100)* c=0.025c \\ \\ 4.9\%\text{ of b}=(4.9)/(100)* b=0.049b \\ \\ 7.5\%\text{ of }s=(7.5)/(100)* s=0.075s \end{gathered}

- We are told that the income from the investments is $10972.50. This implies that:


0.025c+0.049b+0.075s=10972.50

- Lastly, we are also told that $65000 was invested more in bonds than CDs. This implies that:


b=c+65000

- Thus, we have 3 simultaneous equations that we can solve.

- The solution steps for solving the equations are given below:


\begin{gathered} b=c+65000 \\ \text{ Substitute this expression for b into the other two equations,} \\ \\ 0.025c+0.049b+0.075s=10,972.50 \\ 0.025c+0.049(c+65000)+0.075s=10972.50 \\ \text{ Simplifying, we have:} \\ 0.074c+3185+0.075s=10972.50 \\ \text{ Subtract 3185 from both sides} \\ 0.074c+0.075s=10972.50-3185 \\ \\ \therefore0.074c+0.075s=7787.50\text{ \lparen Equation 4\rparen} \\ \\ s+b+c=195,000 \\ s+c+65000+c=195,000 \\ s+2c=195000-65000 \\ s+2c=130000\text{ \lparen Equation 5\rparen} \\ \\ \text{ From Equation 5, we have:} \\ s=130000-2c \\ \text{ Substitute the expression of s into Equation 4} \\ 0.074c+0.075(130000-2c)=7787.50 \\ 0.074c+9750-0.15c=7787.50 \\ -0.076c=7787.50-9750 \\ -0.076c=-1962.50 \\ \text{ Divide both sides by -0.076} \\ \\ (-0.076c)/(-0.076)=(-1962.50)/(-0.076) \\ \\ c=\$25,822.37 \\ \\ \text{ Thus,} \\ s=130000-2c \\ s=130000-2(25,822.37) \\ s=\$78,355.26 \\ \\ b=c+65,000 \\ b=25,822.37+65,000 \\ b=90,822.37 \end{gathered}

Final Answer

The amounts invested are:

Bonds: $90,822.37

Stocks: $78,355.26

CDs: $25,822.37

User Daniel Kng
by
2.8k points