"amount to" or "amounts to"?

[Gromit]

Which of these is correct?

Fourteen nights accommodation and two weeks car rental amount to £756 per person.

Fourteen nights accommodation and two weeks car rental amounts to £756 per person.

Thanks for your help!

[Jamie (K)]

Neither one is correct, because you left out the apostrophes:

Fourteen nights' accommodation and two weeks' car rental amount to £756 per person.

Fourteen nights' accommodation and two weeks' car rental amounts to £756 per person.

Technically, the first one is correct, because you've got two items in the subject, thereby making a plural, so the verb should be "amount".

However, sometimes you'll find people who think of the two items together as one package, and they'd be liable to say "amounts", as if the subject were singular.