Probability of independent events
Assuming the albinism and Down syndrome are independent traits, then the probability of having both traits is the product of the probability of having each trait.
For more information see wiki > probability (especially the section on independent events).
Albinism and Down Syndrome
If (and only if) albinism and Down syndrome are independent events (see below), then the probability fo having Down Syndrome is $\frac{1}{20,000}$ and the probability of having albinism is $\frac{1}{1,250}$, therefore the probability of having both is $\frac{1}{20,000} \frac{1}{1,250} = \frac{1}{20,000 \cdot 1,250} = \frac{1}{2.5\cdot 10^{7}} = 2.5\cdot 10^{-7}$.
So, yes you were correct! Good job!
Validity of the assumption of independence
I want to highlight again the importance of the assumption that albinism and Down syndrome are independent traits. If a person with Down Syndrome has a different probability of being albino then a person that does not have Down Syndrome, then the probability of having both traits will NOT be the product of the probability of having each trait. The only way to know whether these traits are independent is to look at empirical data. I failed to find any evidence of such correlation (but I might have missed it). If this is a homework question, you should be fine just stating Assuming the two traits are independent,...
at the beginning of your answer.