conversations.from: human
conversations.value: Ben starts each day with $50, spends $15 every day and saves the rest. After a few days, his mom doubled his total savings and his dad gave him an additional $10. If he now has $500, How many days have elapsed?
  Give me a solution to this problem
conversations.from: assistant
conversations.value: Let the number of days be x
  He saves $50-$15=$35 each day
  After x days he had saved $35*x=$35x
  His mom doubled his savings to give $35x*2=$70x
  His dad added $10 to give $70x+$10=$500
  Subtracting 10 from both sides of the equation formed gives $70x=490
  Dividing both sides by $70 give x=7 days