I have 5 batteries, 1 is negative. What's the probability I could (A) randomly select 2 good batteries,(B) 1st is good OR 2nd is good OR both are good?

Question

amistre64 · Answer

# success
probability =    ---------
                       # outcomes

amistre64 · Answer

B of course is the more complciated of the two eh

amistre64 · Answer

if there are 4 good batteries;   the prob of selecting a good one is:  4/5,  the prob of selecting a good one the second time .. well, there are 3 out of 4 left on the table.

amistre64 · Answer

B has a sum of probabilites:

gb:  4/5 * 1/4
bg:  1/5 * 4/4
gg:  and this was determined in A

anonymous · Answer

Hi amistre64, thank you for your reply. Can you help me with the probability of selecting 1 good battery and 1 bad battery out of 5 total (4 good + 1 bad) ?

anonymous · Answer

never mind I see your response to B...thanks

amistre64 · Answer

1 good and 1 bad comes it 2 cases:

gb or bg

amistre64 · Answer

:)

anonymous · Answer

Hi again. I have another tough test question. Same 5 batteries.(4 good, 1 bad). The probability of the 1st being good OR the 2nd being good OR both being good?