Answer:
91 tiles are needed
Step-by-step explanation:
The length of the countertop is 3 1/4 ft = 13/4 ft = 13 times the width of a tile.
The width of the countertop is 1 3/4 ft = 7/4 ft = 7 times the width of a tile.
To tile the countertop, Ms Brown will need to fill a rectangle that is 7 rows of 13 tiles, or ...
... 7 × 13 = 91 . . . . tiles
