The number of bacteria was growing in a city exponentially.at 4 pm yesterday , the number of bacteria was 400 and at 6 pm yesterday it was 3600.How many bacteria were there at 7pm yesterday?

• at 4 pm bacteria was 400 and they are growing exponentially so after 2 hours at 6 pm they are 3600 so after 1 hour
  at 5 pm they are 400*3 = 1200
  and after 6 pm they are 1200*3 = 3600
  so after 1 hour at 7pm they are 3600*3 = 108000
• 11 years agoHelpfull: Yes(21) No(0)
• ans is 10800
  growing exponentially.
  so by shortcut it is 3600/400=9.
  9 ans for gap of 2 hours which is exponentially increase so it may b 3,3^2,3^3..
  so after 3 hours means at 7pm its 400*3^3=10800...
  or by logically thinking ...
  So at 4p.m.it is 400...and at 5 p.m it is 400*3=1200, and at 6p.m it is 1200*3=3600, and at 7p.m.it should be 3600*3=10800
• 11 years agoHelpfull: Yes(16) No(0)