The Total solution for NCERT class 6-12
Given:
Total number ofstudents in XI = 20
Total number ofstudents in XII = 20
Total number ofstudents to be selected in a team = 11 (with atleast 5 from class XI and 5 fromclass XII)
Number of ways = (No.of ways of selecting 6 students from class XI and 5 students from class XII) +(No. of ways of selecting 5 students from class XI and 6 students from classXII)
= (20C6 × 20C5)+ (20C5 × 20C6)
= 2 (20C6 × 20C5)ways