
Step-by-step explanation:
The elements of matrices are represented in the form

Here r is the row number and c is the column number.
Given matrix is:
![A = \left[\begin{array}{ccc}3&6&9\\2&4&8\end{array}\right]](https://tex.z-dn.net/?f=A%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D3%266%269%5C%5C2%264%268%5Cend%7Barray%7D%5Cright%5D)
The elements of matrix will be represented by a_{r,c}
We have to find 
Which means that the first row and third column.
The first row is: 3 6 9 and the element in third column is: 9
So,

Keywords: Matrices, Elements
Learn more about matrices at:
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8*40 = 320 * 2 = $640 for the 2 workers
640/2000 = 0.32
labor cost is 32% of the revenue
Set up a proportion:
3/4/24 = 1/x
Cross multiply:
3/4x = 24
Divide 3/4 to both sides or multiply by its reciprocal, 4/3:
x = 24 * 4/3
x = 96/3
x = 32
So you had a total of 32 muffins, now subtract this from the amount that blew away to find out how many you have left:
32 - 24 = 8
So you have 8 muffins left.
Answer : The substances half life in days is, 5.6 days.
Step-by-step explanation :
Half life : It is defined as the amount of time taken by a radioactive material to decay to half of its original value.
All radioactive decays follow first order kinetics.
The relation between the half-life and rate constant is:

where,
k = rate constant = 0.1235 per days
= half-life
Now put all the given values in the above formula, we get:


Thus, the substances half life in days is, 5.6 days.