In a company there are 2/6 java programmer, 1/2 programmers knows c++ and 1/5 programmer doesn't know anything. Then find the fraction of programmers who knows java and c++ both.

• 1/30 is the answer.
  Suppose X number of programers are there in the Company then,
  No. of Programers knows JAVA=x/3
  No. of Programers knows C++=x/2
  Using, n(A Union B)=n(A)+n(B)-n(A intersection B)
  
  We have,
  n(A Union B)x/3+x/2-n(A intersection B)
  
  Therefore No. of Person who don't know any language are ,
  x-{x/3+x/2-n(A intersection B)}=1/5..........(1)
  
  on solving (1),We Have
  n(A intersection B)=x/30
• 10 years agoHelpfull: Yes(0) No(1)
• let us consider 'A' for java programmers
  'B' for c++ programmers
  p(A)=2/6
  p(B)=1/2
  p('A'intersection'B')=1/5
  p(AUB)=2/6+1/2-1/5
  =4/5
• 10 years agoHelpfull: Yes(0) No(0)
• there is another possibility for this question
  the common factor for 6,2,5 is 30
  so,just we assume that 'company have 30 programmers'
  then::::::- java programmers are:10(1/3 form 30=10)
  C++ programmers are:15(1/2 from 30=15)
  don't know programmers:6(1/5 from 30=6)
  so,
  30-6=24
  know both programs=24/30
  =4/5
  
• 10 years agoHelpfull: Yes(0) No(0)
• oh know! they are just confusing........
  P(A)=1-P(A`)
  P(both)=1-P(none)
  =1-(1/5)
  =4/5
  
• 10 years agoHelpfull: Yes(0) No(0)
• 1-(1/5)=4/5 know something.(2/6+1/2)=5/6 know java or c++ or both.5/6-4/5=1/30
  ans is 1/30.
  
• 10 years agoHelpfull: Yes(0) No(0)