School a has so many students in it that it is divided into 15 classes. School a students are known as outstanding students and has an extraordinary memory. From the number of students, a sample is taken for a research as many as 30 students. From 30 students, 10 students are known from the sample have a memory of more than 10,000 sentences. What is the probability that 3 out of 8 students have a memory of more than 10,000 sentences?