http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_w11_qp_62.pdf
Question 7)ii)
if somebody can please explain this to me please.
Question 7)ii)
if somebody can please explain this to me please.
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http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_w12_qp_61.pdf
( Q7 - c part ) I don't get it at all . brain not working ! please help me
Jiyad Ahsan
it because two variables are the same 1 and 1 so only change that can make the difference is 7 so 3C1 shows9 diff fruit pies
3 ppl ---- all gets odd no.
List of odd no. 1 3 5 7 _(9 not possible otherwise all will not get pies!)
Now , lets list possible ways the no. can be divided
1st per 2nd per 3rd per
1 3 5
1 5 3
1 7 1
7 1 1
1 1 7
3 1 5
3 3 3
(See that all combinations add to 9)
Now u c ms says:
1 1 7 = 9C1× 8C1× 7C7 (oe)× 3C1 =216 In above table:here c only 1 out of the three cn get 7 pies so 3C1.
1 3 5 = 9C1× 8C3× 5C5(oe)× 3! = 3024 In above table:here c either can hv 5 or 3 or 1 pie in any order so 3!
3 3 3 = 9C3× 6C3× 3C3 (oe) = 1680
In above table:here c its all getting 3 pie n order doesnt matter!
so you add all n get d final ans!
Hope i cud xplain! Though i myself is not much clear abt y we use 3C1 instd of 3! in the first part ...Bt dat was d explanation we were told @class . A little help there with this Alice123 or syed1995 ASTAR or any1!
it because two variables are the same 1 and 1 so only change that can make the difference is 7 so 3C1 shows
this 1 1 7 or
171 or
711
9 diff fruit pies
3 ppl ---- all gets odd no.
List of odd no. 1 3 5 7 _(9 not possible otherwise all will not get pies!)
Now , lets list possible ways the no. can be divided
1st per 2nd per 3rd per
1 3 5
1 5 3
1 7 1
7 1 1
1 1 7
3 1 5
3 3 3
(See that all combinations add to 9)
Now u c ms says:
1 1 7 = 9C1× 8C1× 7C7 (oe)× 3C1 =216 In above table:here c only 1 out of the three cn get 7 pies so 3C1.
1 3 5 = 9C1× 8C3× 5C5(oe)× 3! = 3024 In above table:here c either can hv 5 or 3 or 1 pie in any order so 3!
3 3 3 = 9C3× 6C3× 3C3 (oe) = 1680
In above table:here c its all getting 3 pie n order doesnt matter!
so you add all n get d final ans!
Hope i cud xplain! Though i myself is not much clear abt y we use 3C1 instd of 3! in the first part ...Bt dat was d explanation we were told @class . A little help there with this Alice123 or syed1995 ASTAR or any1!
please see the answers posted beforeThe weights of letters posted by a certain business are normally distributed with mean 20 g. It is
found that the weights of 94% of the letters are within 12 g of the mean.
(i) Find the standard deviation of the weights of the letters.
w11 61 q5(i)![]()
hey man why do they take 0.97 instead of 0.94?please see the answers posted before
ameen.. yeah fingers crossedNo problem at all! BOL 4 2mrw! Hope everything goes well!! #fingerscrossed
May Allah help us all while we take our exams Ameen!![]()
add square of all i.e. (48.3^2 + 55.2^2 + . . . 64.1^2) then divide this by 11 then subtract mean^2 and then take square roothttp://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_w11_qp_62.pdf
1st question how do u calculate s.d (standard deviation)
its not coming lyk tht ..... the value is coming in negative ... and square root of negative is not possible ....add square of all i.e. (48.3^2 + 55.2^2 + . . . 64.1^2) then divide this by 11 then subtract mean^2 and then take square root
u could have stated the sd formulae -_-add square of all i.e. (48.3^2 + 55.2^2 + . . . 64.1^2) then divide this by 11 then subtract mean^2 and then take square root
whats ur meanits not coming lyk tht ..... the value is coming in negative ... and square root of negative is not possible ....![]()
hey sorry i got it .....add square of all i.e. (48.3^2 + 55.2^2 + . . . 64.1^2) then divide this by 11 then subtract mean^2 and then take square root
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