Turns out that was not a hard problem to solve.

You have to focus all your energy into some problem to solve it.

On my list of problems to solve, oil wasn't even in the top ten.

He has run out of time to wait for the problem to solve itself.

But that was something else, a second problem to solve.

But, he and others said, it was not their problem to solve.

We still have a whole series of problems to solve.

Some say crime is too tough a problem to solve.

They're people to her now, instead of medical problems to solve.

There had been many problems to solve first, of course.