Some of 40%-intensity red paint is replaced with 20% solution of red paint such that the new paint intensity is 20%. What fraction of the original paint was replaced?	Answers
A) 2/5
B) 2/3
C) 1/3
D) 1/2
E) 1/1
Let total paint = 1   Let amount replaced = x   40 (1-x) + 20x = 20   x = 1/1   ANSW1/1R:1/1
<result>E</result>
Some of 40%-intensity red paint is replaced with 20% solution of red paint such that the new paint intensity is 20%. What fraction of the original paint was replaced?