Both arrive after P Waves.
All you have to do is the amount she bought divided by 0.05 and then add the answer you get to the amount she bought each time
Black socks on monday - 3/9 or .33%.
white socks on tuesday - 5/9 or .55%
Explanation: Probability of black socks on Monday:
Total pair of socks: 1 + 3 + 5 = 9
Number of black socks on Monday: 3
3/9 = 1/3 (or divide to get a percentage)
Probability of white socks on Tuesday:
Total pair of socks: 9
Number of white socks on Tuesday: 5
5/9