Two friends race against each other in 100-meter and 800-meter races. Of the 200 races they ran this year, the wins, losses, and ties are shown below. 100 meter (Event D) 800 meter (Event E) A won the race (Event A) 30 50 B won the race (Event B) 60 25 A and B tied (Event T) 10 25 B did not win the race today. What length of race was it more likely to have been? 100 meter or 800 meter? How much more likely?

Let makes the table neater. event D= 100m, even E=800m
                                             (Event D) (Event E) 
A won the race (Event A)     30           50
B won the race (Event B)     60           25 
A and B tied (Event T)          10            25

B did not win the race today. What length of the race was it more likely to have been? The question is asking in what event did the chance of B did not win(lose + ties) is more likely. Then, you need to determine the chance for B did not win in both race.
Chance of B did not win 100-m= 30+10/10=40%
Chance of B did not win 800-m= 50+25/10=75%

The difference would be 75%-40%=35% more likely to lose 800-m race