Answer: 10 plates
Explanation:
The radius of one plate is 8, which implies its diameter is 16.
There must be a 2 inch gap between plates so 16 + 2/2 = 17 cm is how much room each plate needs.
The tray is 40 cm wide. How many 17 cm plates can you fit in that width? 2
The tray is 90 cm long. How many 17 cm plates can you fit in that length? 5
The number of plates that fit on the tray is rows x columns (length x width)
= 2 x 5
= 10