Can any one confirm me what does it means. I know how to calculate width but, not sure how the last number 80 isn't including

Construct a frequency distribution (table) that includes columns showing
each class, class frequency, class midpoint, class relative frequency, and
class cumulative
frequency. The frequency distribution should have 5 classes
and the class width should be rounded to the nearest 5 dollars. The lower
limit of the first class should be $10

Question

Can any one confirm me what does it means. I know how to calculate width but, not sure how the last number 80 isn't including

Construct a frequency distribution (table) that includes columns showing
each class, class frequency, class midpoint, class relative frequency, and
class cumulative
frequency. The frequency distribution should have 5 classes
and the class width should be rounded to the nearest 5 dollars. The lower
limit of the first class should be $10