7.50 X 315 =2362.50 at the lower price
7.75 X 315 = 2441.25 at the higher price
subtract 2362.50 from 2441.25 you get 78.75
Answer:

Step-by-step explanation:
This is a recurring decimal.
Let x = 4.666666... ⇒ (1)
10x = 46.66666... ⇒ (2)
Subtract equation (1) from equation (2)
10x = 46.66666..
-<u> x = 4.666666... </u>
<u> 9x = 42.0000.....</u>
<u />
9x = 42
x = 42/9
= 14/3
=
The answer is 144 over 13
Find how much it grew:
53 - 20 = 33 inches.
Divide the amount it grew by the original length
33/20 = 1.65
Subtract 1:
1.65 - 1 = 0.65
Multiply by 100 for percent:
0.65 x 100 = 65%
The percent increase is 65%