Data Analysis & Probability
11. Mike and his parents went out for dinner. His dad ordered salmon for $9.99, his mom ordered pasta for $8.57, and Mike ordered a grilled cheese sandwich for $6.83. After dinner, Mike's dad paid the bill and included the tip. He paid a total of $30.00, after rounding up to the nearest dollar. What percent tip did Mike's dad leave (round to the nearest percent)?