Two socks are to be picked at random from a drawer containing only black and white socks. What is the probability that both are white?
1. The probability of the first sock being black is 1/3.
2. There are 24 white socks in the drawer.
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black and white socks
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sanju09
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clock60
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got C here
(1) insuffiicent as we don`t know the number of white
(2) insufficient no numberof black
both sufficient
(black)/(black+24)=1/3
black=12, from here we can calculate the prob of picking two white
(24C2)/36C2)
(1) insuffiicent as we don`t know the number of white
(2) insufficient no numberof black
both sufficient
(black)/(black+24)=1/3
black=12, from here we can calculate the prob of picking two white
(24C2)/36C2)
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indiantiger
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1) insuff does not talk about probability of white socks, only info given is nb/(nw+nb) = 1/3
2) total white socks = 24, no info about black socks
insuff
combine 1 and 2
nw = 24
nb/24+nb = 1/3
this will give us nb.
Once we have total number of Black socks and total number of white socks we can calculate the desired probability. As this is a DS question, getting the right value is not necessary.
2) total white socks = 24, no info about black socks
insuff
combine 1 and 2
nw = 24
nb/24+nb = 1/3
this will give us nb.
Once we have total number of Black socks and total number of white socks we can calculate the desired probability. As this is a DS question, getting the right value is not necessary.
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