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:
17 packets
Step-by-step explanation:
So Tanya needs 130 chocolate bars.
But there is 8 in each packet.
So,
130 ÷ 8 = 16.25
16 packets
As you can see, there is a quarter left of chocolates that she needs (0.25). So what she can do is buy 1 more packet then give the quarter of that packet to the children.
So 16 + 1 = 17 packets
A. 199
b. -71
c. -2.25
d. 30
e. -18
f. -4
g. 4
h. 7
i. 0
1. 17
2. 34
3. 62
5. 82
6. 10
7. 18
8. 19
9. 91
Answer:
$300
Step-by-step explanation:
1500 • 20%
1500 • 20/100
15 • 20
300
Hope this helps, good luck! :)