relatively simple
fairly simple
quite simple

If you ask most the answer is fairly simple in its design.

It had been a fairly simple program to build, really.

We've got some good news for you: Taking care of dry skin is fairly simple.

The answer was fairly simple, of course, but I didn't care for it very much.

The basic technology that makes all of this possible is fairly simple.

There's actually a fairly simple way to look at the process.

The provisions of his Will are on the whole fairly simple.

I mean you could even write some fairly simple test programs in fact.

It's a fairly simple thing that does its job very well.

Up to that point it had looked fairly simple, if I could get by without any more murder.