At a community center’s weekend open house, 360 registered visitors had access to two optional sessions: a gardening workshop and a budgeting seminar. How many of the registered visitors attended both sessions?To answer this question, we can consider the implications of the following formula in the context of this question.
Total = A + B - Both + Neither
In this case, we have the following:
360 = Gardening + Budgeting - Both + Neither
(1) Of the 360 registered visitors, 140 attended the gardening workshop, and 180 attended the budgeting seminar.This gives us the following:
360 = 140 + 180 - Both + Neither
40 = - Both + Neither
Since Both and Neither could have many different values, this statement does not provide information sufficient for determining how many attended both sessions.
Insufficient.
(2) The number of registered visitors who attended neither session was 40 greater than the number who attended both sessions.This gives us the following:
360 = Gardening + Budgeting - Both + (Both + 40)
360 = Gardening + Budgeting + 40
320 = Gardening + Budgeting
So, this statement does not indicate how many attended both.
In fact, this statement just says in a different way what we already found using Statement (1). After all, if 40 = - Both + Neither, then Neither = Both + 40.
Insufficient.
Statements (1) and (2) combinedSince the statements say basically the same thing, we know that, combined, they are insufficient for answering the question.
If we want to confirm, we can do the following:
360 = 140 + 180 - Both + (Both + 40)
360 = 140 + 180 + 40
360 = 360
This is true for any value of Both that fits the constraints of the scenario.
Insufficient.
Correct answer: E