noun-part of speech question

Can anyone explain the what part of speech 50 miles per hour is in the sentence below?

"50 Miles per hour is the speed."

Is it a noun? it must be since it is acting as the subject right? What else would it be? Thanks

Quote:

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Originally Posted by alkaspeltzar

Can anyone explain the what part of speech 50 miles per hour is in the sentence below?

"50 Miles per hour is the speed."

Is it a noun? it must be since it is acting as the subject right? What else would it be? Thanks

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It's a noun phrase, or we could say complex subject. The simple subject is "50".

Fifty is the speed.

Fifty miles per hour is the speed.