Assuming you mean all five digit even numbers greater than 50000 along with all six digit even numbers then the given answer is correct.

Start with the five digit numbers ending in 0: there are of those.

The five digit numbers ending in 4: there are again.

But five digit numbers ending in 6: there are of those. Because we can use only the 5 or 7 as the first digit.

That gives 192 five digit even numbers greater than 50000.

Now you count the six digit even numbers

Remember, they cannot have a 0 in the first place.