In a certain alphabet, 20 letters contain a dot and a straight line. 36 letters contain a straight line but do not contain a dot. If that alphabet has 60 letters, all of which contain either a dot or a straight line or both, how many letters contain a dot but do not contain a straight line? Answers:
A) 4	B) 3	C) 14	D) 20	E) 28

Rationale: "we are told that all of the letters contain either a dot or a straight line or both , which implies that there are no letters without a dot and a line ( no line / no dot box = 0 ) . first we find the total # of letters with lines : 20 + 36 = 56 ; next , we find the total # of letters without line : 60 - 56 = 4 ; finally , we find the # of letters that contain a dot but do not contain a straight line : 4 - 0 = 4 ."
Answer: A