SOLUTION: Michael has a drawer containing lots of AA batteries. There are 6 Energizer batteries, 5 Duracell batteries, and 4 Panasonic batteries. If he reaches in and randomly selects 2 batt

Algebra ->  Probability-and-statistics -> SOLUTION: Michael has a drawer containing lots of AA batteries. There are 6 Energizer batteries, 5 Duracell batteries, and 4 Panasonic batteries. If he reaches in and randomly selects 2 batt      Log On


   

Question 1021428: Michael has a drawer containing lots of AA batteries. There are 6 Energizer batteries, 5 Duracell batteries, and 4 Panasonic batteries. If he reaches in and randomly selects 2 batteries, what is the probability they are the same brand?
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!


Hi  

15 batteries: 6E, 5D, 4P

'Chose' 2

P(the same brand) = [6C2 + 5C2 + 4C2]/15C2 = [ 15 + 10 + 6]/105 =  [31]/105= .2952 = 29.52%

note: 6C2 = 6!/2!4! = 6*5/2 = 15