the sum of two numbers is 15 and their geometric mean is 20% lower than arithmetic mean . find the numbers .
a 11,4
b 12,3
c 9,6

• let a and b are two numbers
  so a+b=15 ....(1)
  now GM=AM*80/100
  or, sqrt(ab)=[(a+b)/2]*80/100
  squaring both sides...and after that putting the value of (a+b)...we get.....
  ab=36 now go through from option then we get 12*3=36
  so answer is (b) 12,3
  
  
  
• 9 years agoHelpfull: Yes(13) No(0)
• 12,3
  a.m=12+3/2=7.5
  and g.m=root(12,3)=6
  6 *20/10=1.5
  
  
• 9 years agoHelpfull: Yes(3) No(0)
• given a+b=15
  and we know that airthmatic mean(A.M)=(a+b)/2
  so..AM=15/2=7.5
  and 20% of 7.5=1.5
  so 20% lower than A.M means =7.5-1.5=6
  and geometric mean(G.M) = sqrt(ab)=6
  solve a+b=15
  and sqrt(ab)=6
  u will get ans as a 12,3 as value of a and b.
• 9 years agoHelpfull: Yes(1) No(0)
• let the numbers be x and y
  then x+y=15
  arithmetic mean = 15/2
  let if AM = 100 then GM = 80
  since GM is 20% lower than AM
  now if AM = 15/2
  then GM = (80*15/2)/100 = 6
  and we know that GM = sqrt(x*y) = 6
  so x*y = 36
  so numbers will be 12 and 3
• 9 years agoHelpfull: Yes(1) No(0)
• ans. 12,3
  a+b=15
  GM=(.8AM)
  SQroot(ab)=.8*(a+b)/2
  sqrroot(ab)=6
  ab=36
  and then correct option is b.
• 9 years agoHelpfull: Yes(0) No(0)
• the number is 12 and 3
  because a.m of these two no. is=(12+3)/2=7.5
  and g,m is =root(12*3)=6
  6(gm) is 20% less than 7.5(am)
• 9 years agoHelpfull: Yes(0) No(0)
• in the exam no option for 9
  there is 38 42 50 60
• 9 years agoHelpfull: Yes(0) No(1)