solve please :3 will mark brainliest !!

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[tex] \: [/tex]
6f = $15
8f = $20
10f = ?
Soo :
2f = 5
f = 2,5
10f = 10(2,5) = $25✔
I'm honestly not certain,
but I think for every 2 feet increase, there is a $5 increase, therefore for 10 feet, the cost is $25.
Correct me if I'm wrong.