Question

If the thickness of a pile of 12 cardboard sheets is 45 mm,then how many sheets of the same cardboard would be 90 cm thick?

Answer 1

1cm= 10mm
90cm=900mm
900/45=20
so the answer is 12× 20= 240 sheets

Answer 2

90cm/45mm=900mm/45mm=20 piles. one pile has 12 nos sheet hence total sheet=12×20=240