Answer:
The rope is 24 yards.
Step-by-step explanation:
1 yard = 3 feet
therefore
72 ft / 3 = 24
To solve this problem you must apply the proccedure shown below:
1. You have that
varies jointly as
and
and inversely as the product of
and
. Therefore, you can write the following equation, where
is the constant of proportionality:

2. Now, you must solve for the constant of proportionality, as following:

3. Susbtiute values:


4. Substitute the value of the constant of proportionality into the equation:

The answer is: 
To find out how much more you walked today, you want to find the difference between the two days, which is 10,000-(<span>3y - 2c + 600) = 9400-3y+2c using the distributive property (the negative sign in front of the parenthesis is essentially a -1)</span>