Answer: 10 inches.
Step-by-step explanation:
Since the pecan pie is a circle, you can use this formula:

Where "r" is the radius and
is the central angle of the arc in radians.
If the pecan pie has been cut into 8 equal pieces then the central angle is:

Now you know the arc length and the central angle, then, you can solve for "r" from
:

Substituting values, you get that the radius of the pecan pie rounded to the nearest whole number is:

Answer:
He must work for 115 hours to save at least $1900.
Step-by-step explanation:
The equation that you'll use is 65+16x=1900, with x being hours. I found the answer by using 65+16(115)=1905, which is the closest number you'll get before starting to use half hours and such.