What is wrong with the tasks from the final stage of the Bauman Moscow State Technical University Programming Olympiad?

Question

Programming

Here is one of the tasks, seemingly the simplest, but when you look at the solution, it is absolutely not clear where this solution came from. Moreover, in one of the examples (2 5, 3 3) the answer is 3, although their answers are 4. Can someone explain what the point is, am I stupid, or is there something wrong with their tasks ?

Answer 1

On each day, the first dump truck is loaded by half, in your example 25 33 half 5=2.5 (2.5+0.5 was taken out on day 1, 2.5+0.5 was taken out on day 2)=4