Three friends, A, B, and C were admitted to the same university and will get a place in a dorm. The following are the numbers of available rooms in each of the dorm blocks. Block 1 has 5 rooms; block 2 has 5 rooms; block 3 has 10 rooms. Moreover, each available room has two vacant places. New students are randomly assigned a place in a dorm (each assignment of places is equally likely). What is the probability that all three friends will live in the same block?

Please solve clearly I will give upvote