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Vera_Pavlovna [14]
3 years ago
12

A chemist claims that he has found a chemical formula that will kill a certain bacteria. He claims it will kill half the bacteri

a in 40 seconds, and in the next 40 seconds kill half of the remaining half, and so on. If he is correct, and at a certain time there are 30 bacteria still alive, how many bacteria were alive 4 minutes earlier?
PLEASE EXPLAIN CLEARLY !!
Mathematics
1 answer:
Alex73 [517]3 years ago
7 0

Answer:

4 Minutes = 240 seconds = 6*40 seconds

30*(1/2)^6 = 30*1/64 = 30/64 = 15/32 = 0.5

4 minutes later there is approx. 0 to 1 bacteria alive.

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Answer:

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a= 0.666666...

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so 0.6666 = 2/3

Now we convert 0.75 into fraction form

0.75=\frac{0.75}{1}

Multiply top and bottom by 100 to remove decimal

\frac{75}{100} = \frac{3}{4}

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ziro4ka [17]
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</span>proof:
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