A rational number is called unitary if its numerator is 1; that is, if it is in the form 1/n (n is a positive integer). In how many ways can 1/2 be written as the sum of two unitary rational numbers
I can only think of 2 as follows:
1/3 + 1/6 = 1/2
1/4 + 1/4 =1/2
1/6 + 1/3 =1/2 - which is the same as the first.
+194 
