A Bacteria is doubling at every 4 min. After 40 min 1024 bact. At wat time there will be 256 bacteria?

• Calculating backwards...
  40 min - 1024
  36 min - 512
  32 min - 256
• 12 years agoHelpfull: Yes(27) No(2)
• 1min = 1
  2min = 4
  3min = 8
  so 8 min = 256
  
  or else 256/4 =64= 8^2
• 12 years agoHelpfull: Yes(1) No(5)
• 40 min =1024 bacteria.we have to reduce 1024 to 256...so,reduce the time by 4 mins;
  40mins-4=1024/2i.e,36 mins=512 bacteria;36mins-4=512/2ie,32mins=256 bacteria
• 8 years agoHelpfull: Yes(0) No(0)