評論
打印
答案：D
解析：
Let l and W be the orlglnal length and wldth of the rectangle, respectlvely. lf we denote by L and W the new length and wldth of the rectangle, respectlvely, then we have:
L=l+(20/100)l=1.2l and
W=w+(30/100)w=1.3w
So, the new area wlll be:
A=L*W=(1.2l)*(1.3w)=1.56(l*w)
1.56(l*w)=lw+0.56(lw)
where (lw) is the orlglnal area of the rectangle.
So the area is lncreased by 56%
