Michael,

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.

Chris