Drop down list who's result is dependent on another drop down list

[Paige23]

Good evening.
I am trying to create a drop down list who's result is dependent on another drop down list. Eg. My first drop down list tells me if something has been received or not. My answers in the list are simply 'yes' & 'no'. If the yes button is selected then I wanted the second drop down/cell to say 'n/a'. If no is selected I would then like it to have the options of being able to click 'yes' or 'no' again (in the same cell the 'n/a' would appear). I basically have customers who I need to receive information from and our policy states that they are asked two times for this information to be delivered in a certain time frame. If it is delivered on the first occasion I do not need to ask again (n/a). If not delivered I have to ask again and wait to input yes or no again after a certain time frame.

I hope I have made sense!
I have tried pulling my data within the lists from a separate table and attempting to use an if formula of if x equals yes then be n/a. But it hasn't worked.

Thank you for your time.

 

[Dave87]

try using this formula data validation "Source"
=IF(H1="Yes",$C$2:$C$5,$B$2:$B$5)

Where H1 is the value of your preceding list (I've used Yes and No)
C2:C5 is the dropdown option if H1 is Yes
B2:B5 is the dropdown option if H1 is No

you could also name the ranges

Is this what you are looking for?

 

[Paige23]

That has worked perfectly. Thank you ever so much ?