Reading the passage, we have below info:
- All TopNotch graduates has IQ > 120
- Most students of IQ>120 who apply to >=1 Ivy League schools get accepted to by >=1
- All students of IQ > 150 who apply to >=1 Ivy League schools get accepted by >=1
Quote:
(A) Every graduate of TopNotch High School with an IQ of 150 has been accepted to at least one Ivy-League school.
Note the condition comes with 'who apply to", while this answer failed to include that piece of info, incorrect
Quote:
(B) If a person is a high-school graduate and has an IQ of less than 100, he or she could not have been a student at TopNotch High School.
Be careful with the shell game here: the first part of sentence use "graduate" while the 2nd part uses "student". It could be a student who studied at TopNotch but got transferred to another high school and graduated with IQ < 100, incorrect
Quote:
(C) If a person has an IQ of 130 and is attending an Ivy-League school, it is possible for him or her to have graduated from TopNotch High School.
"It is possible" signals this might be a good contender, and it suffices "all TopNotch graduates has IQ >120". Correct answer
Quote:
(D) At least one graduate from TopNotch high school who has applied to at least one Ivy-League university has been accepted to one of them.
Note we have a gap in given condition "Most students of IQ>120 who apply to >=1 Ivy League schools get accepted to by >=1". Let's say 80% of the students with IQ >120 and actually applied got accepted, there is still a chance (even though very low) that all TopNotch graduates fill in the rest 20% who failed.
Quote:
(E) If a high-school graduate has an IQ of 150 and is not attending an Ivy-League school, then he or she did not apply to one of them.
Shell game again: the answer said "not attending" while all given conditions emphasize "acceptance". The graduate could have been accepted but choose not to attend for whatever reason.