You didn't have to be a rocket scientist to figure those things out.

All of the rocket scientists working on the project were German.

It didn't take a rocket scientist to figure out what had happened.

Did we all have to be, to use the traditional expression, rocket scientists?

You have to be a rocket scientist to figure it out.

She didn't have to be a rocket scientist to guess what it was.

You don't need to be a rocket scientist to figure that out.

You didn't have to be a rocket scientist to figure that one out.

I don't have to be a rocket scientist to figure that one out.

It didn't take a rocket scientist to figure out what was inside.