Out of 20 students studying in a class, 7 are from Maharashtra, 5 are from Karnataka and 3 are from Goa. Four students are to be selected at random. What are the chances that at least one is from Karnataka?
Pick one:
A) 12â„13	B) 11â„13	C) 10â„15	D) 1â„15	E) 51/71
Total possible ways of selecting 4 students out of 20 students =20C4 =4845   The no. of ways of selecting 4 students in which no student belongs to Karnataka = 15C4=1365   âˆ´ Hence no. of ways of selecting at least one student from Karnataka = 20C4 â€“ 15C4 =3480   âˆ´ Probability = 3480â„4845 = 51/71   Answer 51/71
<result>E</result>
Out of 20 students studying in a class, 7 are from Maharashtra, 5 are from Karnataka and 3 are from Goa. Four students are to be selected at random. What are the chances that at least one is from Karnataka?