We are given that C+B=10 Thus, the cases are C=3 and B = 7 C = 4 and B = 6 C = 5 and B = 5 C = 6 and B = 4 C = 7 and B = 3 C = 8 and B = 2 C = 9 and B = 1 C = 10 and B = 0 C = 10 and B = 0Our required case = C = 9 and B = 1 Thus, the required probability