Answer:
7 hours and 15 minutes
Step-by-step explanation:
8 - 3/4 = 7 1/4 hours
WW WI WB WR IW II IB IR BW BI BB BR RW RI RB RR
1/6
There are 6 large squares here, all of which have been shaded but for one.
Thus, the desired fraction is 1/6.