Let s, j, m be the number of apples Sarah, John, Mona bought.
Sarah bought 5 more apples than John did. Thus;
[tex]s=j+5\ldots\ldots\ldots\ldots.......\ldots\ldots\ldots..\text{equation 1}[/tex]
Also, Mona bought 4 less than Sarah. Thus;
[tex]m=s-4\ldots\ldots\ldots\ldots\ldots\ldots\text{.}\mathrm{}\text{equation 2}[/tex]
Expressing m in term of j, we have;
[tex]\begin{gathered} m=j+5-4 \\ m=j+1\ldots\ldots\ldots\ldots\ldots\text{equation 3} \end{gathered}[/tex]
Relating equation 1 and equation 3, we have;
[tex]s>m[/tex]
From equation 3, we have;
[tex]j=m-1\ldots\ldots..\ldots\ldots.\ldots\text{equation 4}[/tex]
Expressing equation 1 in term of j, we have;
[tex]\begin{gathered} s=m-1+5 \\ s=m+4 \end{gathered}[/tex]
Thus, Sarah bought the most.
From equation 3, we can deduce that;
[tex]m>j[/tex]
Thus, John bought the least.
