Test 2 Section 8 - #16 (page 486)

The key here is to plug in a few different numbers and look for a pattern. Start with n=2. If you have a 2x2 square, all 4 of the squares would lie along the boundary, so k=4. Now try a new number. If n=3, you'd have a 3x3 gameboard and only 8 of the squares would be along the boundary (the other square is smack in the middle), so k=8. Try one more number to detect a pattern. When n=4, you have a 4x4 gameboard, and 12 squares make up the border (the other 4 are in the middle), so k=12. So far we have k=4, k=8, and k=12... see the pattern? Multiples of 4. The only answer that's a multiple of 4 is (E).