Okay, all of these pairs add up to 1 or 100%, except for one pair. I'll convert them all to decimals, so all must add up to 1.
3/8 = 0.375
0.625 + 0.375 = 1
62% = 0.62
0.38 + 0.62 = 1
7/8 = 0.875
0.875 + 0.125 = 1
70% = 0.70
1/3 ≈ 0.33
0.70 + 0.33 = 1.03
So the last pair of probabilities(70%, 1/3) does not belong with the other three because it does not add up to 1 like the others.