Thread: Fractions Percentages Problem

Hi,
Given that
A:
Western Australia is 9% of Australias total pop of 17.5 million,
and
B:
City Perth has 6% of Australias total pop of 17.5 million,
and
C :
42% of Australias total pop of 17.5 million live in cities less than 1 mill/rural
And if Perth is the only city with over 1 mill in Western Australia,
Question:
What % percent of the Aussies who live in cities less than 1 mill/rural live in Western Australia??
The answer could be: 3 % ,7 % ,10 % ,14 % , or 28%)

Please let me know what the "right" way to do this is.

My ideas:
(Pop West Aust) - (Pop Perth) to get the amount of the people in W.A. who live in cities less than 1 mill/rural.
worked out:
D:
(9/100) * 17.5 mill - (6/100) * 17.5 mill = 3/100* 17.5 mill

Then, if we are looking for how many (%)of the Aussies who live in cities less than1 mill/rural (52% total) live in W.A.

would we take
D/C that is, (people in W.A who live in cities<1 mill/rural) divided by (Australias total pop of people in cities<1 mill/rural)

or

just take D/17.5 mill ? I think this latter would actually be the % of total Aussie population who live in WA (minus Perth), not the % of the Aussies who live in cities<1 mill/rural

So I get 7.1%
Tell me if I am wrong....
thanx folks!

Let me re-do my reply.

"42% of Australias total pop of 17.5 million live in cities less than 1 mill/rural"

"Western Australia is 9% of Australias total pop of 17.5 million,"
"City Perth has 6% of Australias total pop of 17.5 million,"
"And if Perth is the only city with over 1 mill in Western Australia,"
"What % percent of the Aussies who live in cities less than 1 mill/rural live in Western Australia??"

So, the West Australians that are not in Perth are (9% -6%) = 3% of all Australians.
Let x% of all Australians be those Australians in West Australia that live in cities with less than a million/rural.
By proportion,
42% of 100% Australians = x% of 3% Australians
0.42 = 0.03x
x = 0.42 / 0.03 = 14% ----------answer.

Originally Posted by ticbol

Let me re-do my reply.

"42% of Australias total pop of 17.5 million live in cities less than 1 mill/rural"

"Western Australia is 9% of Australias total pop of 17.5 million,"
"City Perth has 6% of Australias total pop of 17.5 million,"
"And if Perth is the only city with over 1 mill in Western Australia,"
"What % percent of the Aussies who live in cities less than 1 mill/rural live in Western Australia??"

So, the West Australians that are not in Perth are (9% -6%) = 3% of all Australians.
Let x% of all Australians be those Australians in West Australia that live in cities with less than a million/rural.
By proportion,
42% of 100% Australians = x% of 3% Australians
0.42 = 0.03x
x = 0.42 / 0.03 = 14% ----------answer.

I thought that the rest of the Aussies in West Austr. that remain when you subtract Perthians are the population living in cities< 1 mill/rural.
So the 3% would all be living in cities< 1 mill/rural
the question is what % of aussies living in cities< 1 mill/rural live in W.A.

Ideas?

I see I made an error in the last part of my calculations--52 instead of 42!
ok i tried with 42...
% 45/100*17.5 mill = 3/100*17.5 mill
This is where i get 7%

please let me know if you think i'm doign the correct approach, or if the 1st responder is right in that approach. i don't understand that logic too much.

thanks

Let me do it again, by the numbers this time.

Those West Australians who live in cities with less than 1 million people are 3% of 17.5M.
So, those are 0.03(17.5) = 0.525 million

Those Australians who live in cities with less than 1 million people are 42% of 17.5M
So, those are 0.42(17.5) = 7.35 millions.

What percent of 7.35 millions is 0.525 million?
That will be 0.525 / 7.35 = 0.07143.
That, then, is 7.143%

Umm, so that is why I was uncomfortable with my "by proportion" in my first reply. It was not in the form of "ratio = ratio".