Mark borrows 10 dollars from Emily with a simple interest rate of 15% everyday. What is the least integer number of days after which Mark will have to pay her back at least twice as much as he borrowed?
Explanation: 15% if 10 is 1.5 so Mark has to pay Emily $1.5 dollars everyday. After 2 days he owes her $3, after 3 days he will owe her $4.5, until the fifth day when he owes her $10.5. I hope this helps :)
