okay, let's see if I can do this without my calculator
using the Bernoulli Trial equation (I think that's what it's called)
nCr x (p)^r x (q)^n-r
now 5C4 is 5 (Thanks Pascal's triangle)
p is 1/3
q is 2/3
r is 4
n is 5
(1/3)^4 is 1/81
(2/3)^5-4 is just 2/3
5 x 1/81 x 2/3 = 5 x 2/243 = 10/243
This was in my head so check for mistakes