A has 900 people, B has 500, and C has 600. If each division is reduced proportionately until there are 1500 people, how many people will remain in C?

Question

help!!!! · Answer

@TheSmartOne @tom982

anonymous · Answer

So the total population is A+B+C=900+500+600=2000. This needs to be scaled down to 1500, which is a reduction of 500 or 25%. Reduce C by 25% to get your answer.

help!!!! · Answer

450!

anonymous · Answer

Spot on, nice job.

daniel.ohearn1 · Answer

If you reduce c by 25% you will be in turn reducing a and b by greater proportions.  So 450 can't be exactly right.

daniel.ohearn1 · Answer

B and C are directly proportional to A such that A+(5/9)A+(2/3)A= 15   A=648

daniel.ohearn1 · Answer

Now solve for C

daniel.ohearn1 · Answer

A=642 not 648

anonymous · Answer

No, you'll also be reducing A and B by 25% too, the same proportion. 

A=0.75*900=675. B=0.75*500=375. C=0.75*600=450. 

New A+B+C=675+375+450=1500 as required.

anonymous · Answer

Old ratio A:B:C = 9:5:6
New ratio A:B:C = 675:375:450 = 9:5:6 (divide by 75).

Hence the population is still the same proportion of A, B and C.