Adragon was tamed by dumbledore to guard his home. the dragon guarded the home on the condition that dumbledore feed him 4 pieces of meat for every 10 hours. if one cow provides 10 pieces of meat, what is the smallest whole number of cows dumbledore needs to guard his home for 1 month (30 days)?

29 cows

Step-by-step explanation:

First we need to know how many pieces of meat will be needed. But before that, we need to know how many hours are in these 30 days. 24 hours per day so, 30*24=720 hours. 720 hours and 4 pieces of meat per 10 of those hours. We can do 720/10=72, then, 72*4=288. That means we need 288 pieces of meat, if each cow gives you ten, then we can round 288 to the nearest ten which is 290, then, 290/10 is 29. This means that Dumbledore needs 29 whole cows.

(Yer a wizard Harry)