Last month, katie started training for the swim team. she swam 20 laps every day for 18 training days. this month, katie wants to swim 215 more laps than last month. she will swim 3 more laps per training day and add more training days to her monthly schedule. if katie adds 5 training days to her schedule this month, will she swim 215 more laps? if katie adds 10 more training days to her schedule this month, will she swim 215 more laps? if katie adds 6 more training days to her schedule this month, will she swim 215 more laps? build an equation for finding the number of additional training days she needs to swim 215 more laps.