China Naming Network - Solar terms knowledge - A was lucky enough to draw 10 shopping cards of different denominations in an activity.
A was lucky enough to draw 10 shopping cards of different denominations in an activity.
Just look at the reading materials in the textbook.
The solution is not complicated.
The third person won the lottery, and his lottery result was A(2 1), while the first two people's lottery results were A (9,2). * * * three times in total, a A( 10/0,3).
So the result is a (2,1) * a (9,2)/2)/a (10/0,3) =1/5.
In fact, no matter which time the winning ticket is drawn, the probability is the same. Draw lots first, but it's fair to everyone. It asks for the third time, and you can calculate it as 1.