Archie received his medical receipt from his doctor, and he needs to take antibiotics three times a day. If antibiotic costs $3 each and he needs to take it for a week, how much money does he need to buy the antibiotics?
Archie needs $3 x 3 = $<<3*3=9>>9 per day to buy 3 antibiotics.
Therefore Archie needs $9 x 7 = $<<9*7=63>>63 to buy antibiotics that will last for a week.
#### 63