Math CentralQuandaries & Queries


Question from Michael, a parent:

In a group of people,
if 20% of the people are 18-34 years of age, and 30% of the people
are 25-54 years of age.

What are the percentages of people 18-24,25-34,35-54 and other?
Thank you - Mike


More information is needed for a specific answer. The percentage of people aged 25-34 cannot be known from what we have been given. It can range anywhere from 0% to 20%. To see what is going on, try working an example with 10 people in all. According to the data, 2 are 18-34 and 3 are 25-54. This leaves open the possibility that 2, 1, or none of them are aged 25-34. There are then three cases to work out:

CASE 1: 2 are aged 25 to 34. Then none are 18 to 24 and one is 35-54. The percentages are then 0% for 18-24, 20% 25-34, 10% 35-54, and 70% other.

Try the other two cases (for when the total number of people is 10) for yourself; then you should be able to answer the question you asked us by using ranges of percentages.



About Math Central


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.
Quandaries & Queries page Home page University of Regina PIMS