Answer:
157286400 bacteria
Step-by-step explanation:
We are given the following in the question:
The bacteria increases 4 times every 6 hours.
Initially there are 150 bacteria.
Thus, we can write the function for number of bacteria after x hours,

We have to find the number of bacteria in 2.5 days.
1 day = 24 hours
Thus,

Putting x = 60 in the above equation, we get,

Thus, there will be 157286400 bacteria in two and a half days.
Answer: ![\sqrt[5]{y}](https://tex.z-dn.net/?f=%5Csqrt%5B5%5D%7By%7D)
I realize its probably not the largest readable font. If you are having trouble reading it, it is the square root of y; however, there is a tiny little 5 in the upper left corner to indicate a fifth root. So you would read it out as "the fifth root of y"
The rule I'm using is
![x^{1/n} = \sqrt[n]{x}](https://tex.z-dn.net/?f=x%5E%7B1%2Fn%7D%20%3D%20%5Csqrt%5Bn%5D%7Bx%7D)
and the more general rule we could use is
![x^{m/n} = \sqrt[n]{x^m}](https://tex.z-dn.net/?f=x%5E%7Bm%2Fn%7D%20%3D%20%5Csqrt%5Bn%5D%7Bx%5Em%7D)
where m = 1. This rule helps convert from rational exponent form (aka fractional exponents) to radical form.
This kind of experiments are ruled by Bernoulli's formula. If you have probability p of "success", and you want k successes in n trials, the probability is

It's easier to compute the first probability by difference: instead of computing the probability of the event "at least one of the surveyed eats breakfast", let's compute the probability of its contrary: none of them eats breakfast. So, we want 0 successes in 4 trials, with probability of success 0.34. The formula yields

Since the contrary has probability 17%, our event "at least one of the surveyed eats breakfast" has probability 83%.
As for the second question, the event "at least three of the surveyed eats breakfast" is the union of the events "exactly three of the surveyed eats breakfast" and "exactly four of the surveyed eats breakfast". So, we just need to sum their probabilities:
