how many tiles (measuring 350mm x 350mm) are needed to cover an area of 68.5m^2

Question

for a dispute im having with my teachers

Answer 1

1 m² = 10000 cm²

68.5 m² = 685000 cm²

 

35 cm x 35 cm = 1225 cm²

 

You can see that 1225 is not a factor or 685000. So the dimensions of the area are crucial.