Mark wants to tip his server 20% on a $200 check. If his friend agrees to kick in $10, how much should Mark add?
How much should Mark tip? ** First find the total tip amount: 20% * $200 = $<<20*.01*200=40>>40
How much should Mark tip? ** Then subtract the friend's contribution: $40 - $10 = $<<40-10=30>>30
#### 30