BPP Question on Trading income assessment

Hi

I am looking at a question that involves tax adjusted trading profit.

The question in the BPP book States:

“Ronald commenced self employment on 01/01/2016. He has tax adjusted trading profit of £3840 for the 4 month period ended 30 April 2016, and £12060 for the year ended 30 April 2017. These figures are before taking account capital allowances.

My question is do I use Opening year rules here as I don’t think it is used in the answer from BPP. If it is not opening year rules could you let me know why?

The answer give was:
Period ended 30 April 2016 £3840
Period ended 30 April 2017 £12060
Capital Allowances ( £432)
Total (8/12) to 2016/17assessment= £11628 £7752
Answer for 2016/17 Trading Profit = £11592

Capital Allowances were calculated on the year 2016/17 where they bought an asset on 1st September 16 but it seems that they have applied it to the 30 April 17 figure?

Could you please try and explain how they have made the tax assessment?

Many thanks
Emma