Answer:
C
Explanation:
Longest practice is 2 1/2 hours long
Shortest is 1 1/4 hours long
For difference, subtract 1 1/4 from 2 1/2
Convert mixed to improper fractions
(2*2+1)/2 - (1*4+1)/4
5/2 - 5/4
10/4 - 5/4 = 5/4
Change back to mixed fraction
1 1/4