Answer:
0.2103 = 21.03% probability that, in any seven-day week, the computer will crash less than 3 times.
Step-by-step explanation:
In a Poisson distribution, the probability that X represents the number of successes of a random variable is given by the following formula:

In which
x is the number of sucesses
e = 2.71828 is the Euler number
is the mean in the given interval.
Mean of 0.6 times a day
7 day week, so 
What is the probability that, in any seven-day week, the computer will crash less than 3 times? Round your answer to four decimal places.

In which




So

0.2103 = 21.03% probability that, in any seven-day week, the computer will crash less than 3 times.
C.................................................
To solve a quadratic equation like
, you can use the quadratic formula

In your case,
, so the formula becomes

We can simplify the expression:

Since -3 is negative, its square root is computed as

So, the solutions are

C, because 12 squared plus 16 squared equals 544, then you take the square root of
100×(1+0.11÷2)^(2×5)
=170.81
100×e^(0.108×5)
=171.60
So she should choose the account which pays the interest continuously