Can we conclude a set might not be random by checking its subset?

Set A includes 1000 numbers. I checked that half of the numbers in this set is even.

I extracted subset B from set A as follow: any number in set A which starts with 1 is also in set B. (All numbers in B start with 1).

I checked that more than half of the numbers in set B is even.

Half of the numbers in A are even so should we expect the same for B? But more than half of B is even. So can conclude that set A is not random?

If 60% of B are even, can we still conclude A is not generated random?

How if 70% of B are odd?