Rails Active Records using maximum and minimum simultaneously

Below both the query work fines

Event.joins(:visit).where(:page_id => 3).group(:visit_id).minimum('events.time')

Event.joins(:visit).where(:page_id => 3).group(:visit_id).maximum('events.time')

I want to do find the diff maximum('events.time') - minimum('events.time') and group by visit id

For this I am writing below query

Event.joins(:visit).where(:page_id => 3).group(:visit_id).(maximum('events.time') - minimum('events.time'))

I am getting error, (undefined method maximum for main:Object)

can anyone help me out for this active records query