in a science class, 18 student read physic, 25 read mathematics, 23 read chemistry, 9 read physic and mathematics, 10 read mathematics and chemistry and 6 read physic and chemistry. if there are 50 student altogether and 5 student did not read any of the three subject.how many students read .(1) all three subject (2)only mathematics (3) chemistry and mathematics (4) physic and chemistry but not mathematics