Lizzy: Bill and Phil are firehouse Dalmatians. Bill has one less than twice as many spots as Phil. If they have 59 spots combined, how many spots does Bill have?.
Me: Hmmm, let me think. I think this is the detailed solution:
If b is the number of spots Bill has and p is the number of spots Phil has, we know that b + p = 59. We also know that b = 2p - 1. We can substitute the second equation into the first equation to get: 2p - 1 + p = 59. Combining like terms, we get 3p - 1 = 59. Adding 1 to both sides, we get 3p = 60. Dividing both sides by 3, we get p = 20. Substituting this back into the equation b = 2p - 1, we get b = 2 * 20 - 1 = 40 - 1 = 39. Final answer: 39.