500 Minutes
Table 1:
32 - 160
1 - 5 (160/32=5)
100 - 500 (5•100=500)
Table 2:
32 - 160
96 - 480 (3•32=96 so 3•160=480)
4 - 20 (32/8=4 so 160/8=20)
100 - 500 (96+4=100 so 480+20=500)
Explanation: In my opinion, Table A is better because it finds the unit rate immediately. It also takes less steps and makes it easier to find out it'll take 500 minutes for 100 miles.