Out of 15 students 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?	Choose the most appropriate option.
A) 12 / 13	B) 11 / 13	C) 10 / 15	D) 1 / 15	E) 4 / 14

Rationale: total possible ways of selecting 4 students out of 15 = 15 c 4 = ( 15 * 14 * 13 * 12 ) / ( 4 * 3 * 2 * 1 ) = 1365 the number of ways of selecting a 4 students in which no student belongs to karnataka = 10 c 4 number of ways of selecting atleast one student from karnataka = 15 c 4 - 10 c 4 = 1155 probability = 1155 / 1365 = 11 / 13 answer is b
Answer: B