Answer:
63 lbs of dark chocolate
210 lbs of sugar
147 lbs of butter
(that's a lot lol)
Explanation:
So basically you do everything divided by three and multiply that by 21
15 lb dark chocolate in one day is: 3 lbs
30lb: 10lbs
21lbs: 7lbs
and now you multiply each of them by 21 because that's how much days there are in three weeks
3 · 21 = 63
10 · 21 = 210
7 · 21 = 147
(answer above)