math

posted by Taylor

A type of bacteria doubles in number every 12 hours. After 2 days, there are 48 bacteria. How many bacteria were there at the beginning of the first day.

  1. Steve

    2 days is 4 doublings, or 16 times the original amount.

    So, there were 3 to begin.

  2. Taylor

    Thank you Steve.
    But I want to know how to show it.
    Thanks once again

  3. Steve

    every 12 hours, the population doubles. So, if it starts out as p, then after t hours, we have

    p*2^(t/12)

    for t=48, then,

    p*2^(48/12) = 48
    p*2^4 = 48
    16p = 48
    p = 3

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