Mensurationhard · Past Paper
The length of a rectangle is increased by 20% and its breadth is decreased by 20%. The net change in area is:
ANo change
B4% increase
C4% decrease
D2% decrease
✓ Correct Answer: C — 4% decrease
New area = (1.2L) * (0.8B) = 0.96 LB. This is a 4% decrease.
Share this question
More from Mensuration
- A solid lead ball of radius 7 cm was melted and then drawn into a wire of diameter 0.2 cm. Find the length of the wire.
- If the volume of a sphere is 4/3 π cm^3, what is its diameter?
- Four equal circles are described about the four corners of a square of side 14 cm so that each touches two of the others. Find the area of the remaining part of the square.
- Three circles of radius 7 cm each are placed such that each touches the other two. Find the area of the region enclosed by them.
- A conical flask has a radius r and height h. If the slant height is twice the radius, what is the ratio of CSA to base area?