An oil change at instant auto service is regularly $35. Mr. Oliver has a coupon for 25% off. He wants to know the sale price of the service. Which one is correct?

The line plot below represents the number of letters written to overseas pen pals by the students at the waverly middle school.each x represents 10 students. how many students wrote more than 6 and fewer than 20 letters. a.250 b.240 c.230 d.220