1. High Severity & Low Priority: Suppose there is an
application which generates some banking related reports
weekly, monthly, quarterly & yearly by doing some
calculations. In this application, there is a fault while
calculating yearly report. This is a high severity fault but
low priority because this fault can be fixed in the next
release as a change request.
2. Low Severity & High Priority: Suppose there is a spelling
mistake or content issue on the homepage of BT.com website
which has daily lacks of hits all over UK. In this case,
though this fault is not affecting the website or other
functionalities but considering the status and popularity of
the website in the competitive market it is a high priority
fault. 
3. High Severity & High Priority: Suppose there is an
application which gives some banking related reports weekly,
monthly, quarterly & yearly by doing some calculations. In
this application, there is a fault while calculating weekly
report. This is a high severity and high priority fault
because this fault will hamper the functionality of the
application immediately within a week. It should be fixed
urgently. 
4. Low Severity & Low Priority: Suppose there is a spelling
mistake on the pages which has very less hits throughout the
month on any website. This fault can be considered as low
severity and low priority.

Example for High and High serverity will be any 
functionality based ex.Like login page of any function.