Let the 7-digit number number be "ABCDEFG"
Case 1: G = 0
Choose ABCDEF any of 6! ways.
Answer for Case 1: 6! = 720
Case 2. G is not 0.
Choose the 7th digit G any of 3 ways
(as 2, 4 or 6)
Choose the 1st digit A any of 5 ways
(Any of the 5 unchosen digits other than
0 or the digit chosen for the 7th)
Choose the middle 5 digits BCDEF in 5! = 120 ways
Answer for case 2: 3∙5∙5! = 1800
Final answer: 720+1800 = 2520 possible 7-digit even numbers.
Edwin