Audryn added a $12 tip to a $68.73 restaurant bill. what percent tip did she leave? round to the nearest tenth of a percent.

What percent of $68.73 is $12? We can find out what we have to multiply to $68.73 to get $12. We can substitute this with "x". So then, our equation becomes 68.73x = 12. From there, you just do basic algebra. 

You should get 17.4596246% which can then be rounded down to 17% depending on which place you're rounding it by.