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# Help with maths question

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1. At 8a there are 1000 bacteria in a culture.
Every hour, the number of bacteria in the culture increases by a factor of k
Between 10am and 11am the number of bacteria increases by 8000

(a) Show that K^3-K^2=8

(b) Use trial and improvement method to find k correct to 1 decimal place.
You must show all your working.
2. Number of bacteria:
8am: 1000
9am: 1000k
10am: 1000k^2
11am: 1000k^3

Between 10am and 11am the difference is 8000 (given in question)
Therefore, 1000k^3 - 1000k^2 = 8000
This simplifies to k^3 - k^2 = 8

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Updated: April 20, 2016
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