Riddles and Knock, Knock Jokes

Riddles and Knock, Knock Jokes is from the book of Yippee Ti-Yay, Happy Birthday.
 * 1) Scout and Darcy went to Sport's birthday party this morning. They rode on a blue stagecoach with green wheels. At the first stop, two prairie dogs got off, and three prairie dogs got on. At the second stop, one dog got off, and four dogs got on. At the third stop, six bison tried to get on, but they didn't have exact change. No dogs got off. At the fourth stop, Scout and Darcy got off. Here's the question: When was Scout's birthday party?
 * 2) If you spell "most M-O-S-T, and you spell "boast" B-O-A-S-T, and you spell "ghost" G-H-O-S-T, how do you spell what you put in a toaster?
 * 3) Three prairie dogs passed by a table with a birthday cake cut into three slices. Each took one piece of cake, and that left two pieces of cake. How is this possible?