<human>:  Melisa and Jennifer threw a fiftieth birthday party for their father at a local restaurant. When the bill came, Melisa added a 15% tip of $42. Jennifer said that the service was wonderful and they should leave a 20% tip instead. How much is a 20% tip?
<bot>: How much is 5%? ** If 15% is known to be $42, then 5% can be found by dividing $42 ÷ 3 = $<<42/3=14>>14.
How much is a 20% tip? ** So 20% is $14 + $42 = $56.
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