Answer:
1/9
Step-by-step explanation:
1/3*1/3=1/9
'Of' in math means 'multiplied by,' so the equation that we can set up is:
So your answer is 320.
1. Find the unit rate
15 books divided by 5 days = 3 books sold per day.
Since we are looking for how many days it would take the store to sell 21 bucks, we could do 21 (amount of books) divided by 3 (how much books is sold in a day).
Therefore, it will take a week / 7 days to sell 21 books.