The output of the program will be
output: 10/24
this is due to first the inner printf works 'printf ("%d/%d", i, j)' this prints value of 'i' which is 10 and then '/' character then value of 'j' which is 2 and now the inner printf returns the count of printed information which is 4 in this case 1, 0, / and 2. Thus 4 is printed as the value returned by the inner printf after '10/2'.