Question

Please help me i need it right now please

Answer 1

Given:

The rate of interest on three accounts are 7%, 8%, 9%.

She has twice as much money invested at 8% as she does in 7%.

She has three times as much at 9% as she has at 7%.

Total interest for the year is $150.

To find:

Amount invested on each rate.

Solution:

Let x be the amount invested at 7%. Then,

The amount invested at 8% = 2x

The amount invested at 9% = 3x

Total interest for the year is $150.

`x* (7)/(100)+2x* (8)/(100)+3x* (9)/(100)=150`

Multiply both sides by 100.

`7x+16x+27x=15000`

`50x=15000`

Divide both sides by 50.

`x=(15000)/(50)`

`x=300`

The amount invested at 7% is
`300`.

The amount invested at 8% is

`2(300)=600`

The amount invested at 9% is

`3(300)=900`

Thus, the stockbroker invested $300 at 7%, $600 at 8%, and $900 at 9%.