(Scientific Notation) I need help with this

What is the value of x? enter your answer in the box.

The floor of a building consists of 3000 tiles which are rhombus shaped and each of it's diagonals are 45 cm and 30 cm in length. find the total cost of polishing the floor, if the cost per m² is rs. 4.

X=4 / y=100 if x=10 then what is y=?