It's hard to see that when it is computerized. I believe we are right! If not, it's one mark maximum, but we're probably right. I remember reading it in my textbook like 10 minutes before the exam and my maths teacher said:I wanted to ask for the histogram myself. I used 9.95, 10.45 and so on. Q4 in this paper is a similar one and exact 20, 30 are used according to the mark scheme. Both are correct perhaps.
"Yes. Just make sure the difference is only very slight."