Question
please answer all parts
rs 4. A ju x in your room contains 2 dozens of old batteries, eight of which are totally nkbo dead. You don' start picking batteries ane at a time and testing them. (assuming that you lowest term of fractions t put back the battery that you already tested on the pool of batteries). Find the probability of each outcome (8 points) Express answers in A. The first 3 you choose are all good. (2 points) B. At least 1 of the first four works. (2 points) C The first four you pick all don't work (2 points) D. The first 2 work and the next 2 do not work? (2 points)
Explanation / Answer
a)probabilty that first 3 are all good =(16/24)*(15/23)*(14/22)=210/759
b)probabilty =1-P(none of 4 works) =1-(8/24)*(7/23)*(6/22)*(5/21)=754/759
c)probability =1-P(at least one works)=1-754/759=5/759
d)probabilty =(16/24)*(15/23)*(8/22)*(7/21)= 40/759