IKMC 2027 - Grades 5-6 - Self-study SET 14 - Thematic Batch 3 Question 29

Tony colours square grids as in the examples with 4 and 9 grey cells. All four corners are grey, and grey cells are separated by white cells. Following the pictured pattern, how many white cells are in the grid with 25 grey cells?



Continue the exact every-other-row/every-other-column pattern shown in the examples.