Need help about frequency distribution

[feral heart]

I have 2 questions.
When its like 1st image whats the difference between we take class intervals like 60-64,65-69 and 60-65,65-70.

2nd one is,
In the second image we can the class length like that right . but 63 is data in the data set while its the upper boundary of that interval.
Can we use it like that ? If so what is the reason.

Thanks ❤️

[edgy gale]

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@feral heart

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