Q. In a group of 400 readers who read science fiction or literacy works or both, 250 read science fiction and 230 read literacy works. How many read both science fiction and literacy works?

• Consider total number of reader n(S U L) = 400
  People who read science fiction n(S) = 250
  People who read literacy works n(L) = 230
  both science fiction and literacy n(S ∩ L) = ?
  
  n(S U L) = n(S)+ n(L) - n(S ∩ L)
  400 = 250 + 230 - n(S ∩ L)
  n(S ∩ L) = 480 - 400
  n(S ∩ L) = 80
  
  SO People read both science fiction and literacy works are 80
  
• 11 years agoHelpfull: Yes(29) No(2)
• n(S U L)=400,n(S)=250,n(L)=230
  n(S U L) = n(S)+n(L)-n(S ∩ L)
  both science fiction and literacy=n(S ∩ L)
  n(S U L) =n(S)+n(L)-n(S ∩ L)
  400=250+230-n(S ∩ L)
  OR 400=480-n(S ∩ L)
  OR n(S ∩ L)=80
• 11 years agoHelpfull: Yes(12) No(5)
• divide 400 by 2 that is 200 now readers who studies science = 250 which is 50 extra than 200 and 230 studies literacy which is 30 extra than 200 so add 50+30=80
  is the answer.
  |------200-------| total
  |-----------250 science
  230-----------| literacy
  
• 10 years agoHelpfull: Yes(1) No(0)
• (250+230)-400=180
• 10 years agoHelpfull: Yes(0) No(6)
• (250+230)-400=80
• 10 years agoHelpfull: Yes(0) No(1)
• (250+230)-400=480-400=80
• 10 years agoHelpfull: Yes(0) No(1)
• 250+230=480-400=80
  
• 10 years agoHelpfull: Yes(0) No(1)
• let X= both read science fiction and literacy works
  400=250+230-x
  x=480-400
  x=80
  therefore, both read science fiction and literacy works x= 80
• 10 years agoHelpfull: Yes(0) No(0)
• 80 reads both
  (230+250-400)
• 10 years agoHelpfull: Yes(0) No(0)
• very simple total 400 readers,250 science,230 literacy..
  we what know the total science readers so 400-250=150
  literacy 400-230=170,
  150+170=320,reaming is 400-320=80 reads both..
• 10 years agoHelpfull: Yes(0) No(0)
• let, people who read both science and fiction =x
  then, 400=250+230-x
  x=80
• 10 years agoHelpfull: Yes(0) No(0)
• 80
  400=250+230-x
• 10 years agoHelpfull: Yes(0) No(0)
• n(A U B) =400
  n(A) =250
  n(B)=230
  n(A U B) =n(A) + n(B) - n(A ∩ B)
  400 =250+230-n(A ∩ B)
  480-400 =n(A ∩ B)
  80=n(A ∩ B)
• 7 years agoHelpfull: Yes(0) No(0)
• answer is :- 80
  solution:-
  n(S)=250, n(L)=230, n(S or L)=400
  therefore, n(S and L)=(250+230)-400=80.
• 7 years agoHelpfull: Yes(0) No(0)