Five percent of the 300 senior students got a full merit college scholarship and ten percent of them got a half merit scholarship. How many senior students did not get any scholarships? Let's answer step by step:
300 x 5 / 100 = 15 senior students got a full merit scholarship. 300 x 10 / 100 = 30 senior students got a half merit scholarship. So, a total of 15 + 30 = 45 students got scholarships. Therefore, 300 - 45 = 255 senior students did not get any scholarships. The answer: 255.