Given :
Monthly practice time , T=35 hours .
This month, he has practiced 8.5 hours in week 1, 12 hours in week 2, and 5.5 hours in week 3.
To Find :
Many more hours of practice time does Jason need to complete .
Solution :
Number of hours he practice in week 1 , [tex]t_1=8.5\ hours[/tex] .
Number of hours he practice in week 2 , [tex]t_2=12\ hours[/tex] .
Number of hours he practice in week 3 , [tex]t_3=5.5\ hours[/tex] .
Now , number of hours left is :
[tex]t=T-t_1-t_2-t_3\\\\t=35-(8.5+12+5.5)\ hours\\\\t=8\ hours[/tex]
Hence , this is the required solution .