Look at the picture bellow
2 answers:
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Answer:
2 units
Step-by-step explanation:
The given equation of the circle is:
The general equation of the circle is:
Comparing the given equation with the general equation we can say:
g = 4
f = -3
c = 21
The formula for radius of the circle is:
Using these values of the given circle, we get:
Therefore, the length of radius of the given circle is 2.
Answer:
Proved
Step-by-step explanation:
From the given parameters, we have:
i.e. the length of each security numbers
i.e. 2 security numbers
Required
In 513 security numbers, 2 must have matching zeros
To do this, we make use of Pigeonhole principle.
First, we calculate the number of all security numbers not having matching zeros.
Each of the 9 digits can be selected in 2 ways.
2 ways implies that each digit is either 0 or not
So, total selection is:
Apply Pigeonhole principle
The principle states that: suppose there are n items in m containers, where , then there is at least one container that contains more than 1 item.
This means that if there are 512 security number without matching zeros, then there is 1 (i.e. 512 + 1) with matching zeros.