Q5b Probability (1 Viewer)

[mitchh81]

What did everyone get
i) 0.6
ii) 0.1
ii) 0.3
i suck at prob so just to see if i got it right /

 

[someth1ng]

All correct.

 

[damo_g]

That's what i got. Wasn't sure about part (iii).

 

[snorelacks]

That's what I got!

 

[jamesfirst]

I put it in fraction but I got the same for the first 2


Cant remember for the 3rd one.

 

[shutupnsmile]

iii) 1-p(wearing shirt on conseq days)- i forgot my answer it involved 0.3 or 0.7 forgot

 

[kev-is-red]

All the OP's answers are right.

 

[OmmU]

Shouldn't iii) be 0.4?

You multiply the branches of of the tree to get the probability, then add them all together..

EDIT: wrong answer, dont freaaaak... Especially me >.<

 

[shutupnsmile]

Shouldn't iii) be 0.4?

You multiply the branches of of the tree to get the probability, then add them all together..

You have the option of RYR or YRY

P(RYR) = 3/10
P(YRY) = 1/10
Therefore total probability = 4/10

Checked maths textbook to make sure and that is what they do and I think it is the correct method :\

p(RYR)= 3/5 x 2/4 X 2/3 = 2/10

 

[kev-is-red]

Shouldn't iii) be 0.4?

You multiply the branches of of the tree to get the probability, then add them all together..

You have the option of RYR or YRY

P(RYR) = 3/10
P(YRY) = 1/10
Therefore total probability = 4/10

Checked maths textbook to make sure and that is what they do and I think it is the correct method :\

No.

P(R, Y, R) = (3/5).(1/2).(2/3) = 6/30 = 1/5

P(Y, R, Y) = (2/5).(3/4).(1/3) = 6/60 = 1/10

1/5 + 1/10 = 3/10

 

[OmmU]

p(RYR)= 3/5 x 2/4 X 2/3 = 2/10

Fuck. Fingers crossed I wrote the tree diagram right in the exam >.<

 

[asianese]

There goes my HSC.

 

[weirdguy99]

I didn't even draw a tree diagram..I just visualised it in my head.

 

[OmmU]

OmmU Stupiiiieeeeeee xD Oh well I wonder how many other stupid mistakes I made then :|

 

[forthehsc]

No.

P(R, Y, R) = (3/5).(1/2).(2/3) = 6/30 = 1/5

P(Y, R, Y) = (2/5).(3/4).(1/3) = 6/60 = 1/10

1/5 + 1/10 = 3/10

3/10 is the right answer..

 

[lexicon45]

...
I did not read "Kim does not wear a shirt of the same colour on consecutive days..."
Fuck. I did it without replacement..
ah thats 10 marks gone from stupid reading errors from me...

 

[Proteus]

for the third part ab out consecutive days.. I did

P(YRY) = 2/5 x 3/4 x 1/3
P (RYR) = 3/5x2/4x2/3

and added P(YRY)+ P(RYR) together

I think it's right

 

[lexicon45]

i got the wrong answer for ii)
however for iii) is worth 2 marks and, i used complimentary 1 - P(same clothes) with the answer i got from ii)
is it likely they'll give me one mark for correct working out with a wrong answer?

 

[maths94]

for the third part ab out consecutive days.. I did

P(YRY) = 2/5 x 3/4 x 1/3
P (RYR) = 3/5x2/4x2/3

and added P(YRY)+ P(RYR) together

I think it's right

yeh l did taht aswell