Can y’all help me on Thai one
1 answer:
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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.
Answer:
option B
Step-by-step explanation:
9/10 + 6/5 + 3/2...........
We find the difference between the terms
We will get the same difference when we subtract consecutive terms.
so , d= 3/10, a= 9/10
we find the formula for nth term
a_n = a+(n-1) d
we need to find eighth partial sum so we take n=1 to 8
sum of 8 terms ()
So option B is correct