[kttt101]

Doing a past paper and there's one question which i just can't figure out! mega thanks to whoever can figure it out for me


3 types of ship - pangs, quizzers and roodles. All three ships have the same shape and design but differ in size. The cargo capacity depends on the hold volume, while the number of crew required is proportional to the surface area of the deck. A quizzer and roodle taken together have the same length as two pangs, and the crew of a quizzer is just sufficient to provide crews for two pangs and a roodle.

A fully loaded quizzer wishes to transfer all its cargo to smaller pangs and roodles, while minimising the number of crew required for the resultant fleet. How many pangs and roodles are needed?

Hint: note that for objects of any shape, the surface area is proportional to the square of the objects size, and the volume proportional to the cube of its size

thanks again

[boromir9111]

What have you done so far?

[kttt101]

(Original post by boromir9111)
What have you done so far?

I've only got as far as putting what they've said in the question into equation form, I'm not completely sure how to link the different quantities up, even with the hint so i'm not really sure where to go from there

[Mr ABC]

(Original post by kttt101)
I've only got as far as putting what they've said in the question into equation form, I'm not completely sure how to link the different quantities up, even with the hint so i'm not really sure where to go from there

post up your equations?

[kttt101]

(Original post by Mr ABC)
post up your equations?

Quizzer(length) + Roodle(length) = 2Pang(length)

Quizzer(crew) = 2Pang(crew) + Roodle(crew)

length^2 = (k).surface area = (k)crew -> length^2 = k(crew)

[Mr ABC]

(Original post by kttt101)
Quizzer(length) + Roodle(length) = 2Pang(length)

Quizzer(crew) = 2Pang(crew) + Roodle(crew)

length^2 = (k).surface area = (k)crew -> length^2 = k(crew)

say q=length of quizzer etc.

then q=2p+r, or q-r=2p

and q^2=2p^2+r^2, or q^2-r^2=2p^2

[kttt101]

(Original post by Mr ABC)
say q=length of quizzer etc.

then q=2p+r, or q-r=2p

and q^2=2p^2+r^2, or q^2-r^2=2p^2

is that q^2 = (2p)^2 + r^2
ie. q^2 = 4p^2 + r^2

[boromir9111]

yes.

[kttt101]

(Original post by boromir9111)
yes.

lol dunno if thats sarcastic because im such a retard for asking but i've done it now so thanks for your help

[Mr ABC]

(Original post by kttt101)
lol dunno if thats sarcastic because im such a retard for asking but i've done it now so thanks for your help

what did you get for your answer? as it wasn't 4p^2 it was 2p^2

so... (q-r)=2p

and q^2-r^2=2p^2, or (q-r)(q+r)=2(p^2)

[eddieb189]

Reviving a dead thread here, but I just had a look at this question. Did anyone get 3 pangs and 3 roodles?

[BabyMaths]

(Original post by eddieb189)
Reviving a dead thread here, but I just had a look at this question. Did anyone get 3 pangs and 3 roodles?

Yes.