In a long jump qualifying competition, the average jump length of successful competitors was 6.5 meters. The average jump length of unsuccessful competitors was 4.5 meter, and average jump length of all competitors was 4.9 meters. Find the percentage (in %) of successful competitors

• Let s be no. of successful competitors and u be no. of un-successful competitors.
  So, according to que.
  => (s*6.5+u*4.5)/(s+u) = 4.9
  => u=4s
  =>% of successful competitors = s/(s+u)*100
  => s/(s+4s) * 100 = 20% answer
• 10 years agoHelpfull: Yes(3) No(0)
• 25%
  If number of successful competitors=x, unsuccessful competitors=y
  Average=Total jump length/(x+y)=6.5x+4.5y/(x+y)=4.9
  1.6x=0.4y, x/y=1/4=0.25, %(x/y)=0.25*100=25
• 10 years agoHelpfull: Yes(1) No(3)