There are \(10^4=10,000\) ways to choose M, A, T, and H. There is only one way to choose M, A, and H and two ways to choose T in MATHCOUNTS.
That means that there are \(1 \cdot 1 \cdot 1 \cdot 2 = 2\) ways to spell MATH. Then, the probability of getting MATH is
\(\dfrac{2}{10,000} = \boxed{\dfrac{1}{5,000}}.\)
And yes, HeWhoShallNotBeNamed (@Voldemort)s' answer was correct.