Brad ran at 35 mph for 02 hours and then began bicycling at

Brad ran at 3.5 mph for 0.2 hours and then began bicycling at 15 mph. If he went a total of 8.2 miles, how long did he bike?

D=RT
D=3.5*.2
D=.7 miles running.
8.2-.7=15(T-.2)
7.5=15T-3
15T=7.5+3
15T=10.5
T=10.5/15
T=.7 HOURS BIKING.
Proof:
8.2-.2*3.5=15(.7-.2)
8.2-.7=15*.5
7.5=7.5