+0  
 
0
38
1
avatar

A bag has 4 red marbles, 5 white marbles, 6 blue marbles, and 7 green marbles. Three marbles are drawn from the bag (without replacement). What is the probability that they are all the same color?

 Apr 12, 2021
 #1
avatar+118626 
+1

Four different  cases

 

P( all red )   =    4 / 22  *  3/21 * 2/20   =   1/385

 

P( all white)  = 5/22 * 4/21*3/20   =  1/154

 

P( all blue)  =  6/22 * 5/21 * 4/20  =  1/77

 

P(all green)  = 7/22 * 6/21 * 5/20   = 1/44

 

Total probability =  1/385  + 1/154 + 1/77 + 1/44    =    69 /  1540   ≈  4.5%

 

 

cool cool cool

 Apr 12, 2021

47 Online Users

avatar
avatar
avatar