3. a good way to reduce stress is to

 a. go to the mall and buy as many things as you can to take your mind off the stress.
 b. surround yourself with individuals whose company you enjoy.
 c. listen to music at a very loud volume to drown out the stress.
 d. drink a glass of wine to take the edge off.

a, b, c - sides of a triangle

a + b > c

a + c > b

b + c > a

we have a = 5m and b = 11m. substitute:

5 + 11 > c

16 > c → c < 16

5 + c > 11         subtract 5 from both sides

c > 6

11 + c > 5         subtract 11 from both sides

c > -6

c < 16 and c > 6 and c > -6

thereofre your answer is 6m < c < 16m