How many three-digit whole numbers have no 7's and no 9's as digits, and are even?
We have 7 ways to fill the hundreds place [ 7, 9 and 0 cannot be used ]
Then , we have 8 ways to fill the tens digit [ 7 and 9 can't be used]
Finally we have 5 ways to fill the units digit (0, 2,4,6,8 )
So
7 * 8 * 5 = 280 such numbers