Only number 3 plssssssssssssssss

Answer:
(a) 72 tiles
(b) 54 tiles
Step-by-step explanation:
Total perimeter of the pool = 6 + 6 + 4.8 + 4.8 = 21.6 meter.
The tiles are in centimeters so...21.6 m x 100 = 2160 cm.
(a) 2160 divided by 30 = 72
(b) 2160 divided by 40 = 54