A small community football club sells football shirts to members at a subsidized rate in order to raise cash for the club. There was a break-in on the night of 29 December 2027. The treasurer of the club is aware that a number of shirts were stolen, but is not aware of the exact value.

The following information is available:

Data relating to football shirts held by the club: £

Inventory as at 1 December 2027 at cost price 65

Inventory as at 31 December 2027 at cost price 15

Purchases during December 2027 490

Sales during December 2027 500

The club use a uniform mark-up on all shirts of one-third on cost. Calculate the value of the shirts that were stolen on 29 December 2027.