When I asked for any guidance or questions like you normally do when you pair through code (I pair 70% of the time) I was told to reread the instructions. Very little help was given. I ended up finishing the challenge on my own time and sending it in after. 45 minutes to complete a banking challenge with zero feedback is a weird way to be tested on skills. I would assume the company would be interested in how you attack problems and the questions you ask rather than being good at rapidly solving coding katas.