Wrong output in expected output


#1

Input
A : [ 25, 10, 20, 30, 40, 50 ]
B : [ 5, 10, 44 ]
C : 60

Expected Output:
20
(25 according to my understanding)

Can you please explain how it is 20?

Also please explain the following:
A : [ 1, 10 ]
B : [ 1 ]
C : 10

Expected output:
2
(1 according to my understanding)