It would be $10. There is a formula to this "madness". Divide $97.95 by 9.5%. Ignore the rest of the numbers. (I'm pretty sure it has like 7 or 8, but I only went up to 3. Just make sure you have have the whole number, $10). Hope this helps.
No she doesn't have enough money. All you do is multiply 8.60 by .2 which come out to 1.72 and 8.60 plus 1.73 which equals 10.33 so she needs 33 more cents tone able to tip 20%.
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