Just starting lectures in normalisation so this will seem a bit simple to some of you
have a relation in 1NF
carReg make model custNo custName hireDate
R111EEE ford escort c100 smith J 14/05/01
R111EEE ford escort c201 owen P 15/05/01
T666TTT nissan sunny c100 smith J 20/06/01
Y666YYY ford mondeo c413 blatt S 14/05/01
Y666YYY ford mondeo c200 smith J 20/05/01
H888HHH nissan sunny c295 owen P 20/05/01
Y666YYY ford mondeo c413 blatt S 10/06/01
R111EEE ford escort c100 smith J 12/07/01
Assuming a customer can hire only one car on the same date but may hire the same car on different dates and that the functional dependencies represented by the data in the relation will hold for any additional data identify the functional dependencies represented by the data in the relation.
I'm not telling you; telling you this much is a massive help for you.
Look at your keys again, and refer each of them back to the text. One or more of them are supported by the text. One or more of them is not supported by the text. The same is true of the data as well if you refer your keys back to that.