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.

Multiply both sides by 100.


Divide both sides by 50.


The amount invested at 7% is
.
The amount invested at 8% is

The amount invested at 9% is

Thus, the stockbroker invested $300 at 7%, $600 at 8%, and $900 at 9%.
Answer:
Length of rectangular strip = 12
area of rectangular strip = 2*12 = 24
Area of square = x^2 = 12^2 = 144
Step-by-step explanation:
Area of square x^2
area of rectangle is given by length * width
Length of rectangular strip = x
width of rectangular strip = 2
area of rectangular strip = length * width = 2*x = 2x
Area of square piece of paper when rectangular strip is taken away from it
= Area of square - area of rectangular strip
= 
It is given that Area of square piece of paper when rectangular strip is taken away from it is 120 square units.
Thus,

Thus,
either x+10 = 0 or x -12= 0
x = -10 or x = 12
but length cannot be negative hence neglecting x = -10
hence value of x is 12.
Hence,
Length of rectangular strip = 12
area of rectangular strip = 2*12 = 24
Area of square = x^2 = 12^2 = 144
I think it going to be 21/2 or 10 1/2