00:01
This question we want to consider under what circumstances are these functions one to one.
00:05
So first, if the teacher are assigned to their own office.
00:11
So this will be only one to one.
00:13
If we, suppose that we had three offices right now.
00:16
Then if two teachers, teachers say a and teacher b occupied the first office, then this function is clearly not one to one because two teachers are mapped to one office.
00:30
So to make it one to one, we need to delete this b, put it to a new office and i'll take a c will be put in new office as well.
00:39
So a is only one to one if every teacher had their own office, their own office.
00:59
And for b, assigned to chaperone in a group of buses taking students on the field trip...