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Explanation:</h2><h2>
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Here we need to set a system of two linear equations in two variables. So:
- <em>The sum of digits in a two digit number formed by two digits from 1 to 9 is 8:</em>
Let 
be those digits, then:
- <em>If 9 is added to a number then both the digits become equal. find the number:</em>
<em />
<em />
<em />
<em />
But from eq 1:
Substituting y into the expression 1:
The x-value will be found by hit and trial, so:
We have to reject this solution because digits are different.
We have to reject this solution because digits are different.
<em>Then this is a two digit number formed by two equal digits. </em>
Finally, the number is:
44
Answer:
28cm^2
Step-by-step explanation:
By splitting the shape into 2 separate rectangles, you can find that they would be 6cm by 3cm and 5cm by 2cm. doing length x width on both and adding them gives 28cm.
Answer:
A because if you subtract by 8 then you will get zero which would be A
Step-by-step explanation:
Answer:
The standard deviation of the number of runs required is 2447.26
Step-by-step explanation:
For each run, there are only two possible outcomes. Either the program fails, or it does not. The probability of the computer failing during a run is independent of other runs. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
Probability of exactly x sucesses on n repeated trials, with p probability.
The standard deviation for the expected number of trials for r sucesses is:
A computer program has a bug that causes it to fail once in every thousand runs, on average.
This means that 
In an effort to find the bug, independent runs of the program will be made until the program has failed six times. What is the standard deviation of the number of runs required?
This means that r = 6. So
The standard deviation of the number of runs required is 2447.26
