On the first draw, the probability of two signatures is 2/8.
The second time, there is only one left, and just another one has been drawn. The probability is 1/7.
So the probability is 2/8+ 1/7= 1/28.
2。 Two concerts 1 is the probability of Mozart's concert.
The probability of the first draw is 2/8*6/7=3/ 14.
The probability of the second lottery is 6/8*2/7=3/ 14.
So the probability is 3/ 14+3/ 14=3/7.