100 students appeared in 2 tests.60 students passed 1st test. 40 students passed in the 2nd test. 20 students passed in both 1 and 2 tests. what is the probability of the students who failed in both tests? Options
A) 10 %	B) 15 %	C) 20 %	D) 25 %	E) 30 %

Rationale: 20 student passed both two test 40 student passed only 1 st test 20 student passed only 2 nd test so 100 - ( 20 + 40 + 20 ) = 20 student failed in both sub so ans is 20 % answer : c
Answer: C