Answer: 37.5%
Step-by-step explanation:
The probability that Ang wins is 1/4 since he's one person out of the four total. This assumes each person has an equal chance at winning.
Once Ang wins, the chances of getting a mug are 1/2.
So the probability of Ang winning and getting a mug is (1/4)*(1/2) = 1/8
Meanwhile, the probability of Jack winning and getting either prize is 1/4, which we'll add to the previous result to get
1/8 + 1/4 = 1/8 + 2/8 = (1+2)/8 = 3/8
Then convert this to a percentage
3/8 = 0.375 = 37.5%