Camila had a large collection of basketball cards. She gave half of them to her friend Erin and a sixth of them to her brother. She still has 150 cards left. How many cards did she start with?

450 Camila started with 450 cards. She gave Erin half of them (225) and her brother a sixth of them (75). She was left with 150 cards (450 - 225 - 75 = 150). If x = number of cards Camila started with, then x/2 = half the cards and x/6 = one sixth of the cards. 150 = number of cards left. This can be represented as: x - x/2 - x/6 = 150 Multiply by 6 and solve for x 6x - 3x - x = 900 2x = 900 x = 450 = number of cards Camila started with