The tray is 90 cm x 40 cm. Each plate has a radius of 8 cm. There needs to be a 2 cm gap around each plate. How many plates can Nicola fit on the tray?

Answer: 10 plates

Step-by-step 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