Answer:
669.9 ft³
Step-by-step explanation:
The formula for volume of a cone:


The radius is 8; the height is 10.
From here, we can just plug the numbers into the formula.

≈ 
The given series is

Where the first term, a , is 3.
And the difference is constant, that is

So the constant difference, d is 3.
Since the difference is constant, so the given series is arthmetic.
And for explicit rule, we use the formula of nth term, which is

Substituting the values of a and d, we will get

Recursive rule is used to tell us the relationship between previous and current term. And the required rule is

No x=5 since 5 is the input. The input is always equal to x and the output is always equal to y. So x=5 and y=x+5