Math Is Fun Forum

indira

Guest

population problem

A town in India has a population of 20,000 people. Five percent of them are one-legged, and half the others go barefoot. How many sandals are worn in the town?

MathsIsFun

Administrator

Registered: 2005-01-21

Posts: 7,713

Re: population problem

Well, how many unfortunate one-legged citizens in town? 5% of 20,000, which is 5 x 20,000 / 100 = 100,000/100 = 1,000 of them.

And therefore there are 19,000 with two legs.

If half go barefoot then there would be 19,000/2 who wear two sandals and 1,000 who wear one sandal.

19,000/2 x 2 + 1000/2 x 1 = 19,000 + 500 = 19,500.

Is this right?

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"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

Saz000

Guest

Re: population problem

20000 people

5 % have one shoe each                                          = 1000 shoes

PLUS half of the rest (19000/2 = 9500) have
two shoes each (9500 x 2)                                        = 19000 shoes

                                                                   Total    = 20,000 shoes

One thousand one legged people wear
one thousand shoes, not 500!!!

(I think)

MathsIsFun

Administrator

Registered: 2005-01-21

Posts: 7,713

Re: population problem

Good one, Saz000! The original problem said half the OTHERS, whereas I assumed half of all did. So it is saying that EVERY one-legged person wears sandals, so you are right.

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"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

jam-pot

Member

Registered: 2005-04-20

Posts: 142

Re: population problem

um yeah i agree it is a good question and a difficult yet interesting outcome

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the allmighty spatula * want a tip* dont eat yellow snow: the meaning of life is a number and that number is 1