Answer: 25.6
First, notice that there is 1 adult and 2 children.
A normal adult ticket costs 24. But it's 1/3 off, so 24 * 1/3 = 8 off. That means with the Railcard, it only costs 24 - 8 = 16.
Next, one child ticket costs 12. But it's 60% = 3/5 off, so 12 * 3/5 = 7.2 off. That means with the Railcard, it only costs 12 - 7.2 = 4.8.
Remember there are 2 children, so we multiply by 2 to get 4.8 * 2 = 9.6 for the children.
Final answer: 1 adult + 2 children = 16 + 9.6 = 25.6.
Hope that helped,
-sirswagger21