Qualification > Math
STATISTICS
louis:
(1) 3 million people from country A drinking tea.
12 million people from country B drinking tea.
There are 15 million people from country A and B drinking tea.
P ( a person chosen from 15 million who come from country A)
= n ( People from country A who drink tea )
-------------------------------------------------------------------
n ( People from both countries A And B who drink tea )
= 3 millions / 15 millions = 1/5
(2) P(The person chosen does not have sugar in their tea )
= n(person from A drinking tea without sugar) + n(person from B drinking tea without sugar)
--------------------------------------------------------------------------------------------------
n (person from both countries A and B who drink tea)
= (3X 0.7 ) + (12 X 0.35)
-----------------------------
15
= 2.1 + 4.2
------------
15
=0.42
(3) This is the conditional probability
P( The person is from country B | The person does not have sugar in their tea )
= (12 x 0.35)/ 15
-------------------
0.42
= 0.667
candy:
Hey!
do u ppl have any link/resource..for | nCr, nPr, and arrangements | ...where i can understand it better...the pastpaper questions are confusingg!! i really need help and practice on that chapter.....the exam is on wed! :-[
preity:
Candy...mayb u should try this website...http://www.s-cool.co.uk/alevel/maths.html
me@me@me:
--- Quote from: astarmathsandphysics on May 21, 2009, 09:44:34 am ---I meant 5/25 for b since 5 out the 25 that own a car also own a bike
--- End quote ---
i dont think wut u did was right
cz 30 own a car(they dint tell that they own only ca
so 5/30
candy:
Thanks for the link priety! :)
I have a question!! :-[
Six men and three women are standing in a supermarket queue.
(i) How many possible arrangements are there if there are no restrictions on order?
(ii) How many possible arrangements are there if no two of the women are standing next to each
other?
(iii) Three of the people in the queue are chosen to take part in a customer survey. How many different
choices are possible if at least one woman must be included?
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