a traveller walks a certain distance.had he gone half a kilometer an half a kilometer an hour faster,he would have walked it in 4/5 of it time,and had he gone h half a kilometer an hour slower,he would have walked 2 .1/2 hr longer.what is the distance.?

• Distance=15 Km.
  If distance=d & Speed=x,then Normal time=d/x
  Given Condition(I), d/(x+0.5)=(4/5)(d/x), 2d/(2x+1)=4d/5x,x=2 &
  Condition(II), d/(x-0.5)=(d/x)+(5/2),2d(2x-1)=(2d+5x)/2x,or
  2d=10x^2-5x,Substituting x=2,d=15
• 11 years agoHelpfull: Yes(5) No(6)
• @devendra why u substitute this by 2 bro..
• 11 years agoHelpfull: Yes(1) No(0)
• i)d/(x+0.5)=(4/5)*(d/x);
  =>4dx+2d=5dx;
  =>dx=2d;
  =>x=2---------------------------------(i)
  
  ii)d/(x-0.5)=(d/x) + (5/2)
  =>(dx-dx+0.5d)/(x(x-0.5)) = 5/2;
  =>d=5x^2-2.5x;
  Substitute eqn(i) i.e. x=2;
  d=5*2^2-2.5*2;
  d=20-5=15
  So distance is 15
• 11 years agoHelpfull: Yes(1) No(0)