Each side of a rectangular field is diminished by 40%. By

Home » Aptitude » Mensuration » Question

Each side of a rectangular field is diminished by 40%. By how much per cent is the area of the field diminished ?

Using Rule 10,
Let the length and breadth of a rectangle are changed by x% and y% respectively, the effective change in area

=		x + y +	xy		%
			100

Here, x = – 40
y = – 40

∴ Percentage decrease =		-40 - 40 +	40 × 40		%
			100

= (– 80 + 16) % = – 64%
Negative sign shows decrease.