James goes out to eat.  He orders a steak and egg meal for $16.  He is with his friend, who orders chicken fried steak for $14.  His friend pays for half the bill and James pays the tip along with his half of the bill. They tip 20%.  How much did James pay?
The meals cost 16+14=$<T>add(16, 14)=30
So each paid 30/2=$<T>divide(30, 2)=15.0
James left a tip of 30*.2=$<T>multiply(30, 0.2)=6.0
So James paid 15+6=$<T>add(15, 6)=21
