grammar - Relaxed approach in/at/towards solving

What is the difference between the following and are they correct?

1. He took a relaxed approach in solving the problem.


2. He took a relaxed approach at solving the problem.


3. He took a relaxed approach towards solving the problem.

Cheers,
Chris

Answer

Number 1 is valid but uncommon, and 2 would not normally be used in British English. Number 3 is perfectly fine but wouldn't be commonly used. The most commonly-used formation would be:

He took a relaxed approach to solving the problem.