nusha, Banu and Esha run a running race of 100 meters. Anusha is the fastest followed by Banu ans then Esha. Anusha, Banu and Esha maintain constant speeds during the entire race. When Anusha reached the goal post, Banu was 10m behind. When Banu reached the goal post Esha was 10m behind. How far was behind Anusha when the latter reached the goal post.
option
a) 70
b) 81
c) 90
d) 80

• Let Speeds of Anusha be x, Banu= y and Esha= z.
  Therefore 100/x=90/y (time taken is same).
  Again 100/y=90/z.
  Solving z= (81/100)*x. (speed of esha in terms of Anusha).
  Since time taken =100/x.
  So distance traveled by Esha when Anusha is at goal post= (81/100)*x*(100/x)
  =81
• 11 years agoHelpfull: Yes(33) No(3)
• Anusha:Banu = 100:90 and Banu: Esha =100:90 so
  Anusha:Banu:Esha=100:90:81 so ans should be 81m
• 11 years agoHelpfull: Yes(18) No(3)
• 81 is right answer
  anusha s1=100m/t
  banu s2=90m/t
  so s1/s2=10/9.........(1)
  when
  banu s2=100m/t
  Esha s3=90m/t
  s2/s3=10/9....(2)
  multiply 1*2
  s1/s3=100/81;
  so answer is 81
• 11 years agoHelpfull: Yes(9) No(1)
• Speed is distance / time..
  Here when Asha reaches 100 m, banu reaches 90 m. But both take the same time.. Hence
  Asha speed = 100/t ; bhanu speed = 90/t....
  Speeds ratio = 10/9
  Similarly when banu teaches 100 m, esha reaches 90 m. So
  Banu speed = 100 /t ; esha speed = 90/t.
  Speeds ratio = 100/90
  
  Multiply the above two conclusions..
  We get Asha speed / esha speed = 100 / 81....
  Hence when Asha runs 100 metres, esha runs 81 metres
• 9 years agoHelpfull: Yes(3) No(2)
• why ratio would be 100:90:81?
  why 81?
• 11 years agoHelpfull: Yes(2) No(2)
• A:B=100:90
  B:E=100:90
  A:B:E=100:90:(100/90*100/90)
  A:B:E=100:90:81
• 8 years agoHelpfull: Yes(2) No(0)
• ratio of speeds of anusha/banu =100:90
  ratio of speeds of banu/esha=100:90
  ratio of anusha/banu/esha =1000:900:810
  =100:90:81
• 9 years agoHelpfull: Yes(1) No(2)