Answer:
Therefore the ratio of home-team fan to away team fan at 8:00 p.m is
=109:67
Step-by-step explanation:
Initially , total home team fans =1000
and away team fans = 700.
7:00 pm to 8:00 pm = 1 hour = 60 minutes
Given that
 Every 10 minutes the number of arrival home team fans is 15.
Then in 1 minutes the number of arrival home team fans is 
and in 60 minutes the number of arrival home team fans is  
  
                                                                                                  =90
Therefore total home team fans = (90+1000)=1090
Given that
Every 10 minutes 5 fans leave of away team  leave.
then in  1 minutes  fans leave of away team  leave.
  fans leave of away team  leave.
and In 60 minutes  =30  fans leave of away team  leave.
 =30  fans leave of away team  leave.
Since 30 away team fans leave.
Total away team fans = (700-30)=670
Therefore the ratio of home-team fan to away team fan at 8:00 p.m is
=1090:670
=109:67