Answer:
$97.50
Step-by-step explanation:
So we know that $78 is 80% of the regular price because 100% - 20% = 80%.
With this in mind if we divide $78 by 8 we will get $9.75. This shows us that each 10% is $9.75. We can now do $9.75 x 10 which equals $97.50
Hope this helps! :)