start with 38 tiles.
616 3x6 inch tiles are needed to cover exactly 77 square feet.
190
80
68
240
It depends on how big the tiles are.
Tiles that are two feet on a side cover 4 square feet. 378 of them cover 1512 square feet.
76.6 tiles
67 tiles.
It depends on the dimensions of the tiles and their orientation.
192 tiles
start with 38 tiles.
157 18 by 18 tiles are needed to cover 352 square feet.
616 3x6 inch tiles are needed to cover exactly 77 square feet.
Two tiles will suffice since they will cover 36 square feet.
A minimum of 33 tiles, a maximum of 40.