maths and stat(combination)

A transportation company has 8 lorries and 10 drivers available. When it receives 4 orders of one lorry each, how many different selections of lorries and drivers are there to meet the requests?

Below is my work,,
8C4 times 10C4 =14700(but wrong)

but I really dont understand why we need to times the above anwer by 4! so as to get the real answer

Thanks a lot!!!


ans:352800