A rectangular counter is covered with 600 square tiles. The counter could have been covered with 400 tiles 1 cm longer on a side. How do you find the length of a side of the smaller tile?
The side length of the smaller tile is 2 cm
Let the length of 1 of the 600 tiles be
Then Length of counter be
But we are told the length of 1 of the 400 tiles is
So we have: