If a bacteria multiplies itself in to two every second.in an hour there are 5M, at what time it reaches 2.5M?

using your rate = 0:59:59





at 1hr they equal 5million so 1sec beforehand they would have numbered 2.5million





At 1:00:01 there would be 10million and so on

If a bacteria multiplies itself in to two every second.in an hour there are 5M, at what time it reaches 2.5M?
59 min 59 sec
Reply:What time did it start?
Reply:59 minutes 59 seconds
Reply:30 minutes
Reply:hour minus one second.
Reply:Yep, I agree with wombat.
Reply:One hour minus one second. In that final second of the hour, the number doubles from 2.5 M to 5 M.
Reply:1 second before that hour





and everyone who doesn't say a second before has officially got an IQ below 80 which is equal to George Bush!!





And certain vegetables can out think him!
Reply:59 minutes and 59 seconds
Reply:1 sec = 1


2 secs = 2


3 secs = 4


4 secs = 8


11 secs = 10


21 secs = 1,048,256


22 secs = 2.096,512





Just over 22 seconds, not minutes at all.





In an hour there with would be billions of billions of billions.
Reply:Use your brain....if there are 5million in 1 hour then 2.5 million would take half an hour!!!!!!!!!!!!!!!!!





How will you ever learn if you do not put some effort to it!
Reply:if you know that much you should know the answer??
Reply:59 min 59 seconds = 2.5M


after 1 sec i.e. 1 hour = 5M
Reply:Actually it occurs between the 22nd and 23rd second providing none die, and 5 million is attained between the 23rd and 24th second.


22 seconds into multiplying the total would be 2,097,152


23 seconds into multiplying the total would be 4,194,304


24 seconds into multiplying the total would be 8,388,608
Reply:they dont multiply every second they can divide every 20 minutes, but thats pretty much the minimum. you answer is roughly 40 minutes i could work it out properly but i dont want to,


according to your figure of 1 sec it would only take 22 seconds to make wel over 2.5 million and 23 seconds to reach 5 million. using the 20 minute figure that i suggested it would take 6 hours 40 minutes to get to 1 million 7 hours to get to 2 million 7 hours 20 minutes to get to 4 million. so im not sure that helps you that much, but i hope it does,
Reply:30 minutes
Reply:59 min 58 sec
Reply:59 min 59sec
Reply:this is an arithmetic progression....if it doubles every seconds a bacteria reaches 2.5 mil in 59 min 59 sec
Reply:Then we'd have a serious problem!!!





The fastest muliplying bacterium is E.coli which can self-replicate under ideal conditions in 20 minutes using a two-way rolling-circle genome replication technique.





Every two seconds?! I think not!
Reply:It takes one second from the time the 2.5 mil mark is reached.
Reply:time it reaches 2.5m= 60/5


=12 second


=12*2.5


=30 second
Reply:wombat nailed it