There are 15 stepping stones numbered from 1 to 15. A frog jumps from the 1st stone as follows; Every minute it jumps to the 5th stone from where it started - that is from 1st it would go to 6th and from 6th it would go to 11th and from 11th it would go to 16th etc. And another frog jumps from 1st stone in the same manner but it takes 4 minutes for each jump. What would be the number of stepping stones between the two frogs at the 60th minute if they start at 1st step?
a)0 b)14 c)12 d)5

• To find the position of the 1st frog at 60 minute:
  1st minute : 1 + 5 = 6th step
  2nd minute : 6 + 5 = 11th step
  3rd minute : 11 + 5 = 15 + 1 = 1st step
  4th minute : 1 + 5 = 6th step
  5th minute : 6 + 5 = 11th step
  6th minute : 11 + 5 = 15 + 1 = 1st step
  
  The same process is repeated 20 x 3 times.
  
  Then, the jumping positions are
  
  1 6 11
  1 6 11
  1 6 11 and so on.
  
  after 20th cycle it will be in the 1st position
  
  i.e., at 60th minute it will be in the step numbered 1.
  
  Now, to find the position of the 2nd frog at 60 minute:
  
  It takes 4 minutes for each jump.
  
  End of 4 minutes : 1 + 5 = 6th step
  End of 8 minutes : 6 + 5 = 11th step
  End of 12 minutes : 11 + 5 = 15 + 1 = 1st step
  End of 16 minutes : 1 + 5 = 6th step
  End of 20 minute : 6 + 5 = 11th step
  
  To make it easy we have written the above pattern again as follows:
  
  Minutes : 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60
  Steps : 6 11 1 6 11 1 6 11 1 6 11 1 6 11 1
  
  At 60th minute the 2nd frog will be in 1st step.
  
  Thus, the two frogs are in same position in 60th minute.
  Then the number of stepping stones between them is 0.
  Hence, the answer is 0.
• 11 years agoHelpfull: Yes(29) No(1)
• frog 1:
  in 1 min it reaches 6th step.
  in 60mins it will reach 360th step.
  
  frog2:
  in 4 minutes it reaches 6th step.
  in 60 mins it will reach6/4*60=90th step.
  
  now since the total number of steps are 15.
  so 360 mod 15=0.. again 90 mod 15=0.
  so they are on same step.
• 11 years agoHelpfull: Yes(18) No(1)
• frog jumps from 1st stone to 6 then 6 to 11 then 11 to 1 then 1 to 6 so on....
  1st frog- frog reach 1st to 6 in 1 second, in 11 2 sec, in 1 3 sec. so after 60 sec frog will be at 1st stone.
  2nd frog- after 12 sec it will reach 1st stone from 1 to 6 to 11 to 1 ( 4+4+4=12) sec. so after 60 sec frog will be at 1srt stone. no. of steping stone between them is 0.
• 12 years agoHelpfull: Yes(5) No(4)
• in 60 min 1st frog jump 5*60=300step & 2nd frog jump 4*60=240steps so difference is 60steps between them again as there is only 15 steping stone and 60 is divisivle by 15 so diff of steping stone betwn two frog is 0
• 11 years agoHelpfull: Yes(2) No(0)
• 1ststone--6th stone--11th stone---1st stone..
  
  .dis is d cycle for both frogs..in third jump frogs will be back to 1st stone.
  now in 60 minutes 1st frog will jump 60 steps n 2nd frog will jump 15 steps.
  ..
  as 15 n 60 both are divisible by 3..both will be at 1st stone
  differnce=0
• 11 years agoHelpfull: Yes(1) No(0)
• answer is 14.
  because at 60 minutes second frog will be at 15th step. whereas, 1st frog will come to 1st step every 5 minutes later. so after 60 minutes it will again come to 1st step as 60 is fully divisible by 5. thus, the gap is 15-1=14.
• 11 years agoHelpfull: Yes(0) No(5)