Can someone help The cost of buying a used vacuum cleaner Varies depending on his age as shown in the scatterplot describe the trend in the scatterplot and explain your answer

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