Question

A room is 8 meters long and 4 meters wide. how many paving stones each measuring 2.5dm by 2dm are required to pave its floor?

Answer 1

no. of paving stones required = area of floor/area of a stone
convert dimensions into cm
=800×400/25×20
=640
Hence 640 stones are required to pave the floor

Answer 2

Solution :-

Length of the room floor = 8 m or 80 dm (1 meter = 10 decimeter)

Breadth of the room floor = 4 m or 40 dm

Area of the room floor = L*B

⇒ 80*40

= 3200 dm²

Length of each paving stone = 2.5 dm

Breadth of each paving stone = 2 dm

Area of each paving stone = 2.5*2

= 5 dm²

Number of paving stones required = Area of the room floor/Area of each paving stone

⇒ 3200/5

= 640 paving stones

So, 640 paving stones will be required to pave the floor of room.