Terry bought a house for £65,000 on 1 October 2000 and occupied the house as his principal private residence. He lived in the house until 1 October 2006 when he went to stay with relatives in Australia, letting the house in his absence. He did not return until 1 October 2010, when he began using one-quarter of the house for business purposes and the other three-quarters as his residence. This arrangement continued until 1 October 2020 when he sold the house for £190,000. Compute the chargeable gain.