How can i convince my mom to.....?

How can i convince my mom to let me go on a field trip to Busch Gardens,Tampa? they're gonna start selling tickets on Jan.25th-Feb.5th...i have my cell phone so yea..!! oh and the tickets cost's $89 and the field trip is in May!!!! i asked my dad but he said i should ask my mom first because he doesn't live us and i live with my mom so....