Capital Gains tax on death of tennants in common

My father died 2 years ago and owned a house as tennants in common with my mother. On his death, his share was put in trust for me. The house at this time was valued at £280,000, so I owned £140,000 My mother has now died and her share has passed to me. The house was valued at £300,000 for probate purposes but sold at £310,000. Can you please advise how I calculate capital gains tax? Do I have to submit two different claims? Ie one for the gain from my Dads share of the house and one for my mothers share of the house? If so, how do I do this as the online form doesn't seem to allow two different calculations.

Hi hbeech,
You take the 50% value at the time your father died and the other 50% when your mother died added together for your purchase price.
The date acquired will be when you got the first share.
Thank you.