500 or so.
To form three-digit even numbers from the set {2, 3, 5, 6, 7}, we can use the digits 2 or 6 as the last digit (to ensure the number is even). For each case, we can choose the first two digits from the remaining four digits. For three-digit numbers, there are 2 options for the last digit and (4 \times 3 = 12) combinations for the first two digits, resulting in (2 \times 12 = 24) even numbers. For four-digit even numbers, we again have 2 options for the last digit. The first three digits can be selected from the remaining four digits, giving us (4 \times 3 \times 2 = 24) combinations for each last digit. Thus, there are (2 \times 24 = 48) even four-digit numbers. In total, there are (24 + 48 = 72) three-digit and four-digit even numbers that can be formed from the set.
There are 12 such numbers.
9,000
There are 320 such numbers.
There are 7200 such numbers.
2240
500
5*5*4*4 = 400
With a total of 90,000 five digit numbers, we can conclude that there is 45,000 EVEN five digit numbers.
7000 - 999 ie 6001 four digit numbers
900 numbers
There are 12 such numbers.
9,000
There are 320 such numbers.
256 unless you count zero in which case its 625.
90
There are 7200 such numbers.