There are five cards, numbered 1 to 5, in a bag. Two cards are drawn randomly without replacement. Find the probability that
(a) the product of the two numbers is even;
(b) the difference between two numbers is greater than 2.
Question (Probability)
2009-01-14 8:12 am
回答 (1)
2009-01-14 9:31 am
✔ 最佳答案
a) P(the product of the two numbers is even)=1 - P(both of two cards are odd numbers)
=1 - 3C2/5C2 (any 2 cards from 1,3,5 over any 2 cards from five cards)
=1 - 3/10
=7/10
b) P(the difference between two numbers is greater than 2):
These cases are : (1 , 4) (1 , 5) and (2 , 5),total 3 cases
So the answer is 3/5C2 = 3/10
參考: MEME
收錄日期: 2021-04-21 22:03:07
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