Sum of 2 no is 50 and sum of their reciprocal is 1/12. So find these number? [

• let numbers are x & (50-x)
  
  then 1/x + 1/(50-x) = 1/12
  => x(50-x) = 600
  => (x-20)*(x-30) = 0
  => x = 20,30
  
  numbers are 20,30
• 9 years agoHelpfull: Yes(42) No(0)
• let the nos be x and y, then x+y=50
  and 1/x+1/y= 1/12
  => (x+y)/xy= 1/12
  => 50/xy=1/12
  => xy=60 => x(50-x)=60
  => (x-30)(x-20)=0
  => x= 20,30
  hence the nos are 20,30
  by d way i doubt that this was a question from Elitmus... its not an elitmus level question.
  
• 9 years agoHelpfull: Yes(10) No(0)
• first consider two nos. i.e. 'a' and 'b'
  A/q
  a+b=50 --------(1)
  also
  (1/a) + (1/b) = 1/12
  on solving we get
  (a+b)/ab=1/12
  on putting the value from (1) we get
  ab=600
  Now solving through the substitution method will definitely give you the answer but I would say to hold this approach ,because its time consuming method , and use only when your hit and trial method does not work .
  So
  simply recapitulate the values whatever you have
  a+b = 50
  a*b = 600
  so its clearly visible that the values must be 20,30 or vice versa .
• 9 years agoHelpfull: Yes(3) No(0)
• their roots are 20 and 30
  let the numbers be a,b
  a+b=50
  1/a + 1/b = 1/12
  a+b/ab=1/12
  50/ab=1/12
  ab=600
  a(50-a)=600
  a2-50a+600=0
  a=20,30
• 9 years agoHelpfull: Yes(1) No(0)
• 20 and 30 put in the both equation ans is yours
• 9 years agoHelpfull: Yes(0) No(0)
• 1/12 is the sum of reciprocal .
  Make the denominator a multiple of 50.
  1*50/12*50 = 50/600
  Now 600 = 30 *20 which satifies both the criteria .
  So ans is 30,20.
  
• 9 years agoHelpfull: Yes(0) No(0)
• let two numbers be x and 50-x
  then a/c
  1/x+1/(50-x)=1/12
  hence solving this equ we get x=30 and 20
  
• 9 years agoHelpfull: Yes(0) No(0)
• 20+30=50
  1/20*1/30=1/12
• 7 years agoHelpfull: Yes(0) No(0)
• option 1 -may i
• 7 years agoHelpfull: Yes(0) No(0)