conversations.from: human
conversations.value: I need a clearer understanding of how to solve: Every hour Joanne has to collect the coins out of the fountain inside the mall. During the first hour, she collected 15 coins. For the next two hours, she collected 35 coins from the fountain. In the fourth hour, she collected 50 coins from the fountain but she gave 15 of them to her coworker so she could buy a soda. How many coins did she have after the fourth hour?
conversations.from: assistant
conversations.value: 15 coins collected in hour one
  35 coins collected in hour two
  35 coins collected in hour three
  50 coins collected in hour four
  Before giving her coworker some coins there were 15+35+35+50=135 coins
  The number of coins after given 15 to her coworker is 135-15=120