Don’t know if this is an error? Chapter 56, EOC Q #3 & 5 seem to have different formulas in the answer key for calculating n on puts:

Q3: n=(p+ - p-)/(S+ - S-)

Q5: n=(p- - p+)/S+ - S-)

Anyone understand this formula enough to say if this is just an error? For calls and in the text it looks like it should be the first.