Answer
$0.09
Work Step by Step
1) The first step is to find out how many weeks our razors will last. So 10 razors x 1 week = 10 weeks.
2) 10 weeks = 70 days
3) 10 razors cost 6.30 dollars, and since they last 70 days, you would have to divide 6.30 dollars by 70 days, which would give you $0.09.