.the number of bacteria in a test tube doubles every 3 mins.if at the end of
1 hour there are N bacteria in the test tube,at the end of how many minutes were
there exactly N/4 bacteria?
a)51 b)54 c)56 d)58

• b)54 mins
  At 60 mins there are N bacteria
  At 57 mins there are N/2 bacteria
  At 54 mins there are N/4 bacteria
• 11 years agoHelpfull: Yes(21) No(0)
• At 60 mins there are N bacteria
  At 57 mins there are N/2 bacteria
  At 54 mins there are N/4 bacteria
• 11 years agoHelpfull: Yes(6) No(0)
• b) 54
  
  Supoose there is N bacteria in starting in test tube.
  according to question it double in every 3 minutes.
  so,
  at 3 minutes --- > N*2
  at 6 minutes --- > N*2*2
  ......................
  at 60 minutes -> N*2^20
  now in question they are asking in which time how much bacteria in 1/4 of its..
  
  N*2^20) / 2^2 = N * 2^18
  
  so required time is 18*3 = 54 mins
• 5 years agoHelpfull: Yes(0) No(0)