# matrix question - help needed

I am doing revision on matrices and came across this question. The solution (the matrix provided below the question) is there. I am not sure how or why 180 is in the position (1,4) (row and column respectively).

Any help is much appreciated! Thank you

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The answer is in the first sentence:

Each female adult of a particular species of stick insects lays 180 eggs at the start of each month.

Therefore $E_{n+1}=180A_n\Longrightarrow \begin{pmatrix}E_{n+1}\\\vdots\end{pmatrix}=\begin{pmatrix}0&0&0&180\\\vdots&\vdots&\vdots&\vdots\end{pmatrix}\cdot\begin{pmatrix}\vdots\\A_n\end{pmatrix}$.

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