A woman sells to the first customer half her stock of apples and half an apple, to the second customer half an apple and half of her remaining stock and so also to a third and to a fourth customer. She finds that she has now 15 apples left. How many had she at first?

• 15/x = (1-1/2)^4
  15/x = 1/16
  x = 240
  x+15
  240+15 = 255
• 7 years agoHelpfull: Yes(0) No(0)