A geometric series is written as 
, where 
is the first term of the series and 
is the common ratio.
In other words, to compute the next term in the series you have to multiply the previous one by .
Since we know that the first time is 6 (but we don't know the common ratio), the first terms are
.
Let's use the other information, since the last term is 
, we know that 
, otherwise the terms would be bigger and bigger.
The information about the sum tells us that
We have a formula to compute the sum of the powers of a certain variable, namely
So, the equation becomes
The only integer solution to this expression is 
.
If you want to check the result, we have
and the last term is
the expected value for the 3 point shot = (3 * 0.30) + (0 * 0.70) = 0.90
the expected value for the 2 point shot = (2 * 0.48) + (0 * 0.52) = 0.96
the expected value for the 2 point shot is higher than the 3 point shot so he should pass the ball
285 - 60x ; where x represents the number of driving hours.
285 ⇒ <span>The total distance to the state park.
60x </span>⇒<span> </span><span>The number of miles driven after x hours.
60 </span>⇒<span> </span><span>The number of miles driven after 1 hour.
y = 285 - 6x
y </span>⇒<span> </span><span>The number of miles left to drive each day.</span>
The buyer will be paying taxes for 185 days, so will pay
... (185/365)·$8200 = $4156
Your most appropriate choice seems to be $4178, which corresponds to 186 days' taxes.
_____
There are 30 days in each month in the last half of the year, plus 1 additional day in each of July, August, October, and December. The 30th of June also belongs to the buyer (but the 29th, closing day, does not), so there are 180+5 = 185 days for which the buyer must pay taxes. The answer choices don't include that value.
