A certain high school with a total enrollment of 900 students held a science fair for three days last week. How many of the students enrolled in the high school attended the science fair on all three days?
(1) Of the students enrolled in the school, 30 percent attended the science fair on two or more days.
(2) Of the students enrolled in the school, 10 percent of those that attended the science fair on at least one day attended on all three days.
Stmt 1: 30 % attended on two or more days. so 270 students attended at least two days, but you get nothing about three days. IS
Stmt 2: 10 % of those that attended 1 day attended all three days. Since you don't know whether all 900 students attented once, this doesn't help. IS
Together: I still don't know nothing about the number of students in stmt 2 and stmt 1 doesn't help here. So still IS. Hence E.
Looks more complicated than it actually was. some logic thinking and the answer was there