2010020102

SubArea: 
Probability
Level: 
A
Project ID: 
2010020102
Source Problem: 
2010020101
Accepted: 
0
Clonable: 
1
Easy: 
0
An urn contains 19 red balls and 9 blue balls. Find the minimum number of blue balls that must be added so that the probability of drawing a blue ball is greater than 0.65.
27
17
7
47