Why is 'Average time on page' not zero when Bounce Rate is 100%?

Answer

Bounce Rate calculation is based on One Page Sessions/Entry Page Views. A One Page Session is a session that consists of only 1 page view ie. a user starts a session from that page and doesn't open any other page afterwards.

The calculation of metrics "Average Time Per Page" is :?
Average time on page = page_view_time_spent/(total_page_views - exit_page_views)

It is not possible to calculate how long a user stayed on the last page, so exit pages are not taken into account. For this concrete page there were some sessions when it was not exit page (User opened some other pages after viewing it). Then "time_spent" could be calculated for those cases. This time is used for calculation of average time on page.?

For example, if the page 'A' has a 100% Bounce Rate. ?Please see the bounce rate formula above. The denominator is "entry page views". So the rate is calculated only for those pages that started session from page A. But apart from that sessions started from Page A, there were still other sessions and average time on page calculation is based on those sessions, that is on those where it was possible to calculate time on that specific page (=when it was not the last page in session).
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