The electric bill in may was $248.00. in june the bill was $265.00. what is the percent of increase rounded to the nearest hundredth? a. 6.85% b. 6.41% c. 7.21% d. 6.42%

1) May: 248$ and june 265$. The difference is 17$ and then you divide the difference with the old price: 17/ 248 = 6,85% 
2) Same method, the difference is 59$ so 27,44%' 
3) The difference is 9,5$ so you answer is 63,3% 
4) The difference is 10$ divided by the original price: 10/24 = 41,66%