Kangaroo Question (1 Viewer)

[Tommy_69]

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

 

[danieljarvis]

lol ... 5/200 = 50/2000

 

[#23]

lol @ the name of the discussion, kangaroo question. I have no idea, I put a lol

 

[7th Sign]

lol at a biology style questions (like the only use full thing I got out of biology before I dropped )

its simple mate its capture/ re capture...

I thought u said u were smart jk lol

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

 

[Tommy_69]

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...

 

[Tommy_69]

lol ... 5/200 = 50/2000

wtf i still dont understand 200/5 = 40

 

[idontbelieveit]

lol at a biology style questions (like the only use full thing I got out of biology before I dropped )

its simple mate its capture/ re capture...

I thought u said u were smart jk lol

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

Ditto.. I knew it from Bio.. haha

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]

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]

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]

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]

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]

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]

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]

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]

^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]

it's actually fun to do so.

*gasp* lol

i looked at the question, felt a headache coming and coloured in C...

 

[mthommo]

^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.

*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

 

[Danoz The Great]

I did 5/50 = 200
Thus 10% = 200
So 100% = 2000. (c)

 

[Snow_dog]

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]

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