Lizzy: John has started at a job he works every day 10 days ago. So far, he's made $250. How many more days must John work before he makes twice this amount, assuming he makes the same amount every day?.
Me: Hmmm, let me think. I think this is the detailed solution:
John has made $250 in 10 days, so this means he makes $250 / 10 = 25 dollars a day. Since John wants to make double his current amount, this means he wants to make 250 * 2 = 500 dollars. This means John needs to work 500 / 25 = 20 days in total to make 500. As John has already worked 10 days, this means he needs to work 20 - 10 = 10 more days to make his goal. Final answer: 10.