Body: Danny collects bottle caps. He found 30 bottle caps at the park while he threw away 63 old ones. Now he has 42 bottle caps in his collection.
Question: How many more bottle caps did danny throw away than those he found at the park?
question_concat: Danny collects bottle caps. He found 30 bottle caps at the park while he threw away 63 old ones. Now he has 42 bottle caps in his collection. How many more bottle caps did danny throw away than those he found at the park?