To calculate the number of different combinations without repetition of 11 representatives out of 15, you can use the binomial coefficient formula, also known as "n choose k," which is denoted as C(n, k). In this case, n represents the total number of representatives (15), and k represents the number of representatives chosen (11).
C(15, 11) = 15! / (11!(15 - 11)!)
Now, calculate the combinations:
C(15, 11) = 15! / (11!(4!))
C(15, 11) = (15 × 14 × 13 × 12) / (4 × 3 × 2 × 1)
C(15, 11) = 32,760 / 24
C(15, 11) = 1,365
So, there are 1,365 different combinations without repetition of 11 representatives out of 15.
The correct option is **Option 1: 1,365.**