Economics homework help: discount rates?

[firefly]

I am having trouble interpreting some economics homework regarding discount rates. "The discount rate tells us how much money in the future is worth now." The equation for figuring out the present value of money in the future is:

x/(1+r)^n (x=money in the future, r=discount rate, n=years)

An example of one of the homework questions: If your discount rate is 6%, do you prefer $107450 in 10 years' time or $183576 in 21 years' time?

I find this to be a personal preference question, but there is a right or wrong answer. So, my question is, which way am I suppose to look at this question? I calculated that for the 10 year one the present value is $60,000, and for the 21 year one the present value is $54,000 - the 10 year one is worth more today. But, going a step further, I found the ratio of each future value to its present value, and the 21 year one has a higher ratio for future money to present money.

Does anyone know which way to approach this?

Thank you!