C( 100， 10)+C(90， 10)+.。 . +C( 10， 10)
1, the probability of randomly selecting a box from ten boxes, including two defective products.
The method of randomly selecting a box from ten boxes is,
[C( 100， 10)+C(90， 10)+.。 . +C( 10， 10)]*C( 10， 1)
The probability of containing two defective products
=C(98，8)*C(2，2)/{[C( 100， 10)+C(90， 10)+.。 . +C( 10， 10)]*C( 10， 1)}
2. The probability that two defective products are packed in the same box in one day.
The first defective product scored 10, the first product scored 10, and * * scored 10 = 100.
Two defective products are packed in one box, because there are 10 boxes, so there are 10 possibilities, so
Probability of two defective products in the same box =10/(10 *10) =110.