1/48 of a week
Explanation:Number of days in a week = 7
Number of hours in a day = 24 hours
Total hours in a week = 7(24) = 168 hours
3 1/2 hours = 7/2 hours
The fraction: (7/2)/(total hours in a week)
[tex]\begin{gathered} \text{The fraction = }\frac{\frac{7}{2}}{168}=\text{ }\frac{7}{2}\div168 \\ \text{The fraction =}\frac{7}{2}\times\frac{1}{168} \\ \text{The fraction = 1/48} \end{gathered}[/tex]The fraction is 1/48 of a week
