Answer:
9.75 hours
Step-by-step explanation:
If Rob drove 35% of the time and Mark drove the remainder of the time, the total is 100 %
100-35 = 65
so Mark drove 65% of the time
The total time driven was 15 hours, so we multiply the total time driven by the percentage of time that Mark drove to find the number of hours that Mark drove.
15 * 65%
15*.65
9.75 hours
