6:15, I got that because every 2 out of 5 tiles is white, so it’s basically 2/5, we have to get the denominator (5) to 15. So we have to multiply 3 on both sides. Because 5*3=15 and what we do to the bottom also happens to the top. So 2*3=6. So every 6 tiles out of 15 will be white. The ratio will be 6:15. Hope that helps
