Kangaroo Question (1 Viewer)

Tommy_69

Old Member
Joined
Sep 24, 2004
Messages
492
Location
Sydney
Gender
Male
HSC
2005
Ive tried working it out a million times I simply cannot get the bloody answer. I guessed it correctly in the exam which was C (2000) but i duno how u get this figure its really bugging me
 

#23

Member
Joined
Jul 9, 2005
Messages
191
Location
Uranus
Gender
Male
HSC
2005
lol @ the name of the discussion, kangaroo question. I have no idea, I put a lol
 

7th Sign

Active Member
Joined
Sep 15, 2004
Messages
2,366
Location
Sydney
Gender
Male
HSC
2005
lol at a biology style questions (like the only use full thing I got out of biology before I dropped :D)

its simple mate its capture/ re capture...

I thought u said u were smart :rolleyes: jk lol

ezy q but hope u got the other ok...
 

Tommy_69

Old Member
Joined
Sep 24, 2004
Messages
492
Location
Sydney
Gender
Male
HSC
2005
I came into the exam with the formula for "capture/recapture" which is

Si x S2
_____
Tagged

it didnt work although. shhhh i still got 93%. nice guess though...
 
Joined
Oct 15, 2005
Messages
39
Gender
Female
HSC
2005
7th Sign said:
lol at a biology style questions (like the only use full thing I got out of biology before I dropped :D)

its simple mate its capture/ re capture...

I thought u said u were smart :rolleyes: jk lol

ezy q but hope u got the other ok...
Ditto.. I knew it from Bio.. haha


Tommy_69 said:
wtf i still dont understand 200/5 = 40
If you still are having trouble, this is how I did it..

He released the 50. Caught back 200 and 5 were tagged. 5/200 = 1/40.. so therefore the original 50 is 1/40 of the estimated number of kangaroos. 50 x 40 = 2000.
 

Gummy_bear

Member
Joined
Oct 29, 2004
Messages
495
Location
Central coast
Gender
Female
HSC
2005
i did:

no. first tagged times no. 2nd tagged over number tagged in recapture.

50 times 200 over 5 = 2000

This is from the formula my teacher gave me.
 

meh05

New Member
Joined
May 20, 2005
Messages
22
Tommy_69 said:
I came into the exam with the formula for "capture/recapture" which is

Si x S2
_____
Tagged

it didnt work although. shhhh i still got 93%. nice guess though...
my bio friend used this too. she got it right. i didn't use it tho, just figured it out

in every 200, 5 were tagged. 50 divided by 5 = 10. 200 times 10 = 2000.
 

mthommo

New Member
Joined
Oct 6, 2005
Messages
22
Location
under a rock
Gender
Male
HSC
2005
in capture-recapture, the percentage of the second sample (200 kangas) that the amount of recaptured tagged 'things' (for lack of a better word) are (5 were tagged) is the percentage of the total population that the number of 'things' from the first sample (50 kangas) represents

ie. 5 is 2.5% of 200 and therefore 50 (the first sample) is 2.5% of the total poplulation.
To work out the total pop. just divide 50 by 2.5 and multiply by 100 and voila!
TOTAL POP = 2000 skippies
 

Mandy101

Member
Joined
Feb 17, 2005
Messages
255
Gender
Female
HSC
2005
I did it like this:

He tagged 50, and when he recaptured 200, only 5 were tagged

5/200 = 50/x (x = total number of kangaroos)

50/5 = 10

10x 200 = 2000
 

mthommo

New Member
Joined
Oct 6, 2005
Messages
22
Location
under a rock
Gender
Male
HSC
2005
Mandy101 said:
I did it like this:

He tagged 50, and when he recaptured 200, only 5 were tagged

5/200 = 50/x (x = total number of kangaroos)

50/5 = 10

10x 200 = 2000
or u could do it that way lol...i was just trying to explain capture-recapture

therefore: mandys is easier
 

Mandy101

Member
Joined
Feb 17, 2005
Messages
255
Gender
Female
HSC
2005
Haha, I dropped to general at the end of year 11 having done a year of 2 unit, and that damn capture-recapture was the one thing I couldn't bloody do. So I made sure I knew it easily and simply for the exam!
 

mthommo

New Member
Joined
Oct 6, 2005
Messages
22
Location
under a rock
Gender
Male
HSC
2005
Mandy101 said:
Haha, I dropped to general at the end of year 11 having done a year of 2 unit, and that damn capture-recapture was the one thing I couldn't bloody do. So I made sure I knew it easily and simply for the exam!

good move...who the hells gonna use calculus anyway...i know my career will involve catching, tagging and recapturing kangaroos and the like..hehe
 

Mandy101

Member
Joined
Feb 17, 2005
Messages
255
Gender
Female
HSC
2005
^LOL. Moving to general was the best thing I ever did. I felt physically pained during 2unit maths lessons - I couldn't see the point in learning about numbers that didn't exist. General is so much more practical and when I can actually understand what it is I'm trying to find, it's actually fun to do so.
 

mthommo

New Member
Joined
Oct 6, 2005
Messages
22
Location
under a rock
Gender
Male
HSC
2005
Mandy101 said:
^LOL. Moving to general was the best thing I ever did. I felt physically pained during 2unit maths lessons - I couldn't see the point in learning about numbers that didn't exist. General is so much more practical and when I can actually understand what it is I'm trying to find, it's actually fun to do so.
xxFiveWords said:
*gasp* lol

i looked at the question, felt a headache coming and coloured in C...
Geez i wouldnt go as far to say its fun, but its definitely more practical and prob more enjoyable than 2 unit...yeh with that q i knew how to do it but couldnt ben bothered so i made an educated guess..and luckily i was right! giggity
 

Snow_dog

Member
Joined
Jul 12, 2005
Messages
64
Gender
Female
HSC
2005
lol hated this question still dunno hwo to work it otu and never will bother to find out but i picked 2000 lol and got it right WOOHOO!
haha i put 200 :S just fixed it :O
 

Shanan

Lumen Ex Tenebris
Joined
Aug 31, 2004
Messages
16
Location
Armidale
Gender
Female
HSC
2005
Not that it matters, because we you will never have to do one of those questions again, but for those visual students.

Draw a circle (pretending that is the first catch, i.e 50 roos), the draw a second circle which slightly overlaps the first, this circle represents the 2nd cath (i.e 200 roos). Therefore the overlapping area must be the 5 roos which were captured twice. So look at the diagram and divide 50 by 5, then the answer (10) by 200.

It sounds confusing but if you draw it, it will hopefully make more sense
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top