Final answer:
To find the number of orchids that were not sold, divide the total cost of the sold orchids by the cost of each orchid. Subtract the number of sold orchids from the total number of orchids in the greenhouse. There were 32 orchids that were not sold.
Step-by-step explanation:
To find the number of orchids that were not sold, we first need to determine the total number of orchids that were sold. We know that the total cost of the sold orchids is £1344, and each orchid costs £5.25. So, we divide £1344 by £5.25 to find the number of orchids that were sold: £1344 / £5.25 = 256.
Now that we know 256 orchids were sold, we can subtract this number from the total number of orchids to find the number that was not sold. There are 16 rows of orchids with 18 plants in each row, so the total number of orchids in the greenhouse is 16 x 18 = 288. Therefore, the number of orchids that were not sold is 288 - 256 = 32.
So, there were 32 orchids that were not sold in the greenhouse.