when we drop a ball from height of 24 it bounce back its half height and repeat until stop then how much total distance will travel until stop.

Option :-a>36
b>48
c>72
d> forget

• c > 72
  assume that the ball comes to rest at infinity
  
  total distance travelled before coming to rest = 24+(12+12)+(6+6)+(3+3)+(1.5+ 1.5)+ ... upto infinity
  
  = 24 + 2*(12 + 6 + 3 + 1.5 + ...)
  = 24 + 2*[12/(1- 1/2)] [sum of infinite GP = a/(1-r), here a = 12, r = 1/2]
  = 24 + 48
  = 72
  
• 10 years agoHelpfull: Yes(20) No(0)
• 72 correct answer
  24+12+12+6+6....
  24+(24+12+6+3..)gp of infinite terms
  sum is:a/1-r
  24+(24/1-0.5)=72
• 10 years agoHelpfull: Yes(3) No(0)
• C>72
• 10 years agoHelpfull: Yes(1) No(0)
• 72 is the right answer
• 10 years agoHelpfull: Yes(1) No(0)
• option d was can not determine
• 10 years agoHelpfull: Yes(0) No(3)
• c>72
  In this question there are two infinite GPs(GP representing the falling distance and GP representing rising distances)
  using a/1-r formula
  (24+12+6+3.......up to infinity)+(12+6+3+......infinity)
  a1=24, a2=12, r=1/2
  (a1/1-r)+(a2/1-r)
  =[24/1-(1/2)]+[12/1-(1/2)]
  =48+24
  =72
  
• 10 years agoHelpfull: Yes(0) No(0)