Hi, 1,000,000,000÷395,815 = 2,526 feet
It would take them 17 hours if they worked together, but it could be 1 hour too.
The given angle is opposite the longest given side, so there is 1 solution.
For an explicit formula in its simplified form, we must evaluate the first two terms.
For

,

, and

. We see that the common difference is

, and

, so we write,

.
The correct answer is
B.