Answer:
36.58% probability that one of the devices fail
Step-by-step explanation:
For each device, there are only two possible outcomes. Either it fails, or it does not fail. The probability of a device failling is independent of other devices. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which
is the number of different combinations of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.
A total of 15 devices will be used.
This means that 
Assume that each device has a probability of 0.05 of failure during the course of the monitoring period.
This means that 
What is the probability that one of the devices fail?
This is 


36.58% probability that one of the devices fail
Answer:
I think the answer is$12 - $3 = $9
the amount u need is $9 to have the complete amount u need to purchase the ticket
53: 800 and 900
54: 700 and 800
55: 500 and 600
56: 2,771,100 and 2,771,200
57: 90,120,000 and 90,120,100
58: 631,900 and 632,000
59: 93,300 and 93,400
60: 200 and 300
61: 900 and 1000
62: 39,576,700 and 39,576,800
63: 24,900 and 25,000
64: 471,100 and 471,200
If you round to the nearest thousands then it would be 4988000.