Answer:
Dollar weighted yield 21.09%
Time weighted yield  11.52%
Explanation:
Dollar weigthed:
Date Capital      Weight Subtotal
Jan 1st     100,000    1 100,000
March 1st -50,000 Â Â 0.83 Â -41,666.66667
May 1st      50,000   0.67  33,333.33333
Dec 31th              91,666.66667
Average capital: 91,666.67
Return: Â Â Â Â Â Â Â 111,000
Rate: 111.000 / 91.667 - 1 = 0,21090
Time weighted:
102,000 / 100,000 -1 = 0.02 from Jan 1st to March 1st
Then 52,500 / 52,000 -1 = 0,0096 From March 1st to May 1st
Finally 111,000 / 102,500 -1 = 0.082926 From May 1st to Dec 31th
weighted Return:
1.02 x 1.0096 x 1.082926 - 1 = 0,115189 = 0.1152 = 11.52%