Final answer:
The cost of an adult ticket is £11 and the cost of a child ticket is £8.50.
Step-by-step explanation:
To find the cost of an adult ticket and a child ticket, we need to set up a system of equations. Let's say the cost of an adult ticket is 'a' and the cost of a child ticket is 'c'.
From the given information, we can set up the first equation as: 3a + 4c = 67 .
The second equation can be set up as: 5a + 6c = 106 (Jones family).
Now, we can solve these equations simultaneously to find the values of 'a' and 'c'.
Multiplying the first equation by 5 and the second equation by 3 will give us:
15a + 20c = 335,
15a + 18c = 318.
Subtracting the second equation from the first, we get:
2c = 17. Therefore, c = 17/2 = 8.5.
Substituting the value of 'c' back into the first equation, we can find the value of 'a'.
3a + 4(8.5) = 67.
3a + 34 = 67.
3a = 67 - 34.
3a = 33.
a = 33/3 = 11.
So, the cost of an adult ticket is £11 and the cost of a child ticket is £8.50.