Annual allowance

Dear tutor:
Ted is a sole trader. His gross contributions to his personal pension scheme have been as follows:
2018/19 £16,000
2019/20 £36,000
2020/21 £25,000
In 2021/22, Ted will have taxable trading profits of about £100,000 and wishes to make a large pension contribution in January 2022. He has no other sources of income.
Required
1 What is the maximum gross tax relievable pension contribution Ted can make in January
2022, taking into consideration any brought forward annual allowance?
2If Ted makes a gross personal pension contribution of £43,000 in January 2022, what are the unused annual allowances he could carry forward to 2022/23?

I want to ask that how to calculate the second question?Thank you!