Among 100 students,32 study Maths,20 study Phy,45 study Bio,15 study Math&Bio,7 study Math&Phy,10 study Phy&Bio,30 do not study any of the 3 subjects. (1)Find the no:of stdents studying all 3 subjects? (2)Find the no:of students studying exactly one of the 3 subjects?
2006-10-27 20:51:21 · 2 answers · asked by rachel 1 in Science & Mathematics ➔ Mathematics
n(M) = 32
n(P) = 20
n(B) = 45
n(M∩B) = 15
n(M∩P) = 7
n(B∩P) = 10
n(MUPUB) = 100 - 30 = 70
n(MUPUB) = n(M) + n(P) + n(B) - n(M∩B) -n(M∩P) -n(B∩P) +n(M∩B∩P)
or,70 = 32 + 20 + 45 - 15 - 7 - 10 + n(M∩B∩P)
or, n(M∩B∩P) = 5 [the no:of stdents studying all 3 subjects]
Exactly one of the 3 subjects
= n(MUPUB) - n(M∩B) -n(M∩P) -n(B∩P) -n(M∩B∩P)
=70 - 15 - 7 - 10 - 5
=33
2006-10-27 20:56:48 · answer #1 · answered by The Potter Boy 3 · 1⤊ 1⤋
kindly do ur own home work
2006-10-28 04:06:05 · answer #2 · answered by Munna Bhai 2 · 0⤊ 1⤋