31 August, 02:50

# Bacteria X has a growth rate of 160 % per hour. Some amount of bacteria X are accidentally introduced into some egg salad. Two hours after contamination, there were 45,000 bacteria X in the egg salad.Find the initial number of bacteria X introduced into the egg salad:Estimate the number of bacteria in the food 3 hours after contamination.

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1. 31 August, 04:38
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3 hours after contamination: 72,798

Step-by-step explanation:

We know that the growth rate is 160% (or 1.6 in decimal form)

This means that if we start with a quantity A initially, after one hour we will have a quantity A*1.6 of bacteria.

After another hour, we will have a quantity (A*1.6) * 1.6 = A*1.6^2 of bacteria.

Then we can model this with an exponential equation:

B (t) = A*1.6^t

where t is the time in hours.

We know that when t = 2, we have:

45,000 = A*1.6^2

Here we can solve it for A, which is the initial number of bacteria X.

A = 45,500 / (1.6^2) = 17,773,4

That we can round down, because we need whole numbers, so the initial number of bacteria X in the egg salad is A = 17,773

If we want to find the number of bacteria 3 hours after the contamination, we need to use t = 3.

B (t) = 17,773*1.6^t

B (3) = 17,773*1.6^3 = 72,798.2

That again, we need to round to the next whole number, so we round down.

B (3) = 72,798