Answer: The cost of a single ticket is £6.30.
Step-by-step explanation: The group bought 4 tickets and got one for free, which means they paid for 3 tickets. If each of them paid £6.30, then the total amount paid is 4 x £6.30 = £25.20.
To find the cost of a single ticket, we can divide the total paid by the number of tickets bought, which is 4:
£25.20 ÷ 4 = £6.30
Therefore, the cost of a single ticket is £6.30.