Respuesta :
Answer:
The amounts of three parts of the investment are 18000, 6000, 5000 respectively.
Step-by-step explanation:
An investment of $29,000 was made by a business club.
Let the amount of first and second investment be x and y respectively. So, the amount of third investment is (29000-x-y).
The first part of the investment earned 8% interest, the second 6%, and the third 9%. Total interest from the investments was $ 2250.
[tex]0.08x+0.06y+0.09(29000-x-y)=2250[/tex]
On simplification we get
[tex]-0.01x-0.03y+2610=2250[/tex]
[tex]-0.01x-0.03y=2250-2610[/tex]
[tex]-0.01x-0.03y=-360[/tex]
[tex]0.01x+0.03y=360[/tex] ..... (1)
The interest from the first investment was 4 times the interest from the second.
[tex]0.08x=4(0.06y)[/tex]
[tex]0.08x=0.24y[/tex]
[tex]x=3y[/tex] .... (2)
From (1) and (2) we get
[tex]0.01(3y)+0.03y=360[/tex]
[tex]0.03y+0.03y=360[/tex]
[tex]0.06y=360[/tex]
Divide both sides by 0.06.
[tex]y=6000[/tex]
Put this value in equation (2).
[tex]x=3(6000)=18000[/tex]
The amount of third investment is
[tex]29000-x-y=29000-18000-6000=5000[/tex]
Therefore the amounts of three parts of the investment are 18000, 6000, 5000 respectively.
