First I converted M to CM.
Then I got the new area in cm. 300x200= 60 000 cm²
Then I divided the new area by the number of tiles.
60 000 ÷ 384 = 156. 25 cm
156.25cm² is the area of one tile.
Then I found the square root of that area to give me a side length.
√156.25 = 12.5 cm
*12.5 cm is the side lengths for each tile*