15. Software testing team ALPHA found 30 defects in the rst week, 14 in the second week and 8 in the third week, a total of 52. In the same amount of intensive testing, team OMEGA found 48 defects. Of those, 39 defects were discovered by both teams. Thus a total of (52 + 48 39) = 61 defects were known. What is the estimate of the number of undiscovered defects remaining in the system? . Two defects left. Three defects left. Five defects left. Thirteen defects left. wwcw> None of the above