Answer :
a lot...
Total even numbers: 4⋅6⋅5⋅4=4804⋅6⋅5⋅4=480
Total 3-digit even numbers: 3⋅5⋅4⋅1=603⋅5⋅4⋅1=60
Total 4-digit even numbers: 480−60=420
Total even numbers: 4⋅6⋅5⋅4=4804⋅6⋅5⋅4=480
Total 3-digit even numbers: 3⋅5⋅4⋅1=603⋅5⋅4⋅1=60
Total 4-digit even numbers: 480−60=420