Select all of the following that are a direct variation.

songs are 99 cents each to download.
tickets for rides at the fair are $1 each.
arcade games are 50 cents or $1.
to go tubing it is $5 to rent the tube and $7 for each hour.

Only these are direct variations:

Songs are 99 cents each to download.
Tickets for rides at the fair are $1 each.

Because, for each of them, the total value will be always the product of the number of items times a constant (the unit price).

 

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