Key Principles

Question 1

Method for solving set problems where you need to find the number in either set (set A or set B)

Answer 1

Question 2

Method for 3 overlapping set problems when the # of unique items is known. Draw out the circles, with the overlaps, and use the formula

Answer 2

Question 3

Method for 3 overlapping set problems when the # of unique items is unknown. Just use the formula

Answer 3

Question 4

Rules of thumb for solving venn diagram questions:

1. If the question stem does not tell us the # of elements belonging to “exactly two” sets in the question, then we draw out the circles and use the formula when total # of unique elements is known.
2. If we are given the combined sum of “Exactly two” sets, then we use the formula when total # of unique elements is unknown

Answer 4

1. If the question stem does not tell us the # of elements belonging to “exactly two” sets in the question, then we draw out the circles and use the formula when total # of unique elements is known.
2. If we are given the combined sum of “Exactly two” sets, then we use the formula when total # of unique elements is unknown