A special lottery is to be
held to select the student
風
who will live in the only
deluxe room in a
dormitory. There are 100 seniors, 150
juniors, and 200 sophomores who
applied. Each senior's name is placed in
the lottery 3 times; each junior's name, 2
times; and each sophomore's name, 1
time. What is the probability that a
senior's name will be chosen?