Validation List with If statement

Hello, I have a validation list in columns E,F,I,L and M (No, Yes, N/A) I would like to put an if statement in columns F-M along with the validation list. So in F3 I would like to enter =if(E3="N/A","N/A"). Basically I would like if E2 = N/A than F2,I2,L2 and M2 are N/A. Any help would be appreciated. Thank you.

A cell can contain either a constant or a formula, never both simultaneously.

Data Validation is in essence a constant - as such you can not have a formula in the same cell as the Data Validation.

If you wish for the constants to default based on prior selections being modified you will need to use VBA I'm afraid (the Change Event - toggling Application.Events as appropriate)