Student: What is the % change in the area of a rectangle when its length increases by 20% and its width decreases by 20%?
Options:
(A) 0%
(B) 20% increase
(C) 20% decrease
(D) 4% decrease
(E) Insufficient data.
Another student: Let's say, hmmm...
(12/10)*(8/10) = 96/100 of original area
96/100 is a 4% decrease from 100/100 -> Final answer: (D).