Here is a question that I stumbled upon (and the solution to it, my reasoning follows after the image):
I answered "The two quantities are equal". My reasoning was as follows: the question mentions standard deviation so I assumed (tell me if I'm wrong) that the population follows a normal distribution. Because it says the population "limits" are 17-57 for town A, then the average must be in the middle so $(17+57)/2=37$. For Town B the same reasoning follows and I get $(16+58)/2=37$. Therefore the average ages must be the same.
... In writing this, maybe I found my mistake (please tell me if I am correct): the bell curve does not have "limits"... so even if the distribution may be normal, the ages are free to be scattered in whatever way along the bell curve, and thus the averages follow to perhaps be different (so the answer is "the relationship cannot be determined").
The mean depends on distribution. Therefore the assumption is not valid since it is not given in the problem. therefore sufficient information is not given is the correct answer.