If 75% of a class of 40 students can sing and only 20% cannot dance, the maximum number of students who can neither sing nor dance is
a) 0 b) 6 c) 18 d) None of these

• i think it will be 8
  as it is asked niether
  so common terms will be taken..
  ie 8
• 12 years agoHelpfull: Yes(11) No(4)
• 75 % of 40 =30 thatss can sing ...
  20% of 40 = 8 thats cannot dance ...
  students who neither sing nor dance = 10+8 =18...
• 12 years agoHelpfull: Yes(10) No(10)
• Number of student that can sing is .75* 40 =30.
  Then the number of student that can't sing is 40-30 = 10
  Number of student that can't dance = 0.2* 40 =8.
  Then the number of student that can dance is 40-8 =32.
  
  Then the maximum number that can't neither song or dance are 10+8 = 18
• 8 years agoHelpfull: Yes(3) No(0)
• it should be 6
• 12 years agoHelpfull: Yes(2) No(7)
• i guess 18 would be the answer...
• 12 years agoHelpfull: Yes(1) No(4)
• I think ans wil be d)
  Let A is a event of can sing = (40*75)/100 = 30. so,P(A)=30/40=3/4.
  Let B is a event of can dance= (40*(100-20))/100 = 32.so,P(B)=32/40=4/5.
  now Student neither sing nor dance = P(AUB)'
  1-P(A intersection B)=1 - P(A)P(B).[as both are independent events]
  1-(3*4/4*5)=2/5.
  so,ans is 40*2/5=16 students.
• 11 years agoHelpfull: Yes(1) No(0)
• it is d.none of these
  bcz out of 40 people 30 knows singing nd 8 people dont know dance for maximise the no dnace no singing we wil consider 8 people dnt know singing so finaly we get 8.ans is 8
• 8 years agoHelpfull: Yes(1) No(0)
• 75% of 40 can sing
  i.e. 25% cannot sing
  = 25/100 × 40 = 10 cannot sing
  
  20% cannot dance i.e. 20/100 × 40 can not dance
  = 8 can not dance
  
  Total = 10+8 =18
• 8 years agoHelpfull: Yes(0) No(0)
• 30 students know how to sing in that 8 students don't know how to dance but they can sing. Only 2 persons neither sing nor dance. answer is option d
• 6 years agoHelpfull: Yes(0) No(0)