In a class there are 55 pupil, out of them 10 are in debate only and 18 in singing only. Then how many in both?  Options:  A) 132  B) 26  C) 17  D) 11  E) 12

Rationale: explanation : total pupil = 55 debate + singing = 10 + 18 = 28 the intersection for two = 55 â € “ 10 â € “ 28 = 17 play both games . answer : c
Answer: C