Sam is training for the marathon. He drove 13 miles from his home to the Grey Hills Park and then ran 6 miles to Red Rock, retraced his path back for 2 miles, and then ran 3 miles to Rock Creek. If he is then n miles from home, what is the range of possible values for n?
Choose the correct choice from the following choices:
A) 1 ≤ n ≤23
B) 3 ≤ n ≤21
C) 5 ≤ n ≤19
D) 6 ≤ n ≤20
E) 9 ≤ n ≤15
ANSWER: C To find the maximum and minimum range for his distance from home, assume that he traveled either directly toward his home or directly away from his home. The range then is between 13+6-2+3= 
<gadget id="calculator">13+6-2+3</gadget>
<output>20</output>
20 for the maximum, and   13-6+2-3= 
<gadget id="calculator">  13-6+2-3</gadget>
<output>6</output>
6 for the minimum, so 6 ≤ n ≤20 is the answer
<result>D</result>
Sam is training for the marathon. He drove 13 miles from his home to the Grey Hills Park and then ran 6 miles to Red Rock, retraced his path back for 2 miles, and then ran 3 miles to Rock Creek. If he is then n miles from home, what is the range of possible values for n?