Last set of questions in this section.

When number noun combinations are used, they are always hyphenated.
The hike was eight hours to the temple.
Question - If "eight hours" is an object with eight being an adjective and hours being a noun, why isn't there a hyphen in "eight hours" i.e. "eight-hours"?

These tickets cost forty dollars.
Same question as the previous sentence.

It was an eight-hour hike to the temple.
Question - Here, is "eight-hour" an adjective to the noun hike?

Is it correct to put a hyphen in below as -
The hike was twenty-eight hours to the temple.


These are forty-dollar tickets.
Same question as the previous sentence.

Thanks in advance!!!