Which equation should I use to find the average value of three average values?

When I want to find the average value of three sets of averages, which equation correctly represents the calculation? Why?

((a/b) + (c/d) + (e/f))/3

or

(a + c + e)/(b + d + f)


Example:
(5/2 + 7/3 + 11/5)/3 = 2.344444

or

(5+7+11)/(2+3+5)= 2.300000