Answer:
30 people ordered apple pie
Step-by-step explanation:
one third of the total people:
180/3 = 60
subtract the people who ordered ice cream, so that we have the total people who ordered pie:
180-60= 120
divide the total people by 4 to find the people who ordered apple pie
120/4 = 30
Substitute x with the limits:
13
192/2= 96 g after 7h
96/2=48 g after 14h
48/2= 24 g after 21h
9........I will post process in comments because you are needing this right now