Question 46
How many square slabs each with side 90 cm are needed to cover a floor of area 81 sq m?
Given, side of square slab = 90 cm
∴ Area of square slab = Side × Side = 90× 90 = 8100 sq cm
But according to the question, area = 81 sq m
∵ 1m = 100 cm
1 sq m = 100×100 sq cm
1 sq m = 10000 cm
and 81 sq m = 81×10000 sq cm = 810000 sq cm
Now, number of slabs = Area of floorArea of one square slab=8100008100 = 100
Number of slabs = 100