Lizzy: Archie is playing with his marbles outside. He loses 60% of them into the street. Of the remaining ones, he loses half down a sewer. If he has 20 left, how many did he start with?.
Me: Hmmm, let me think. I think this is the detailed solution:
He had 40 before losing them into the sewer because 20 x 2 = 40. He started with 100 because 40 / .4 = 100. Final answer: 100.