Simplest

Russell was a brilliant philosopher, but even the simplest practical task was quite beyond him.

Other things being equal, the simplest explanation is the best.

She is ignorant of even the simplest facts about science.

She is ignorant of even the simplest fact about science.

I have the simplest tastes. I am always satisfied with the best.

The first and the simplest emotion which we discover in the human mind is Curiosity.

My memory is failing; I can never seem to remember even the simplest of instructions.

The simplest sentences are the most elegant ones.

Physics is concerned with only the simplest cases.

It's the translations which seem to be the simplest that are often the most complex.