How many stones will it take to build the wall shown if each stoke measured 6 1/2 in x 15 1/2 in. Including mortar. Please help me on this. I'm so confused.

240 stokes
Explanation
Step 1
find the area of the wall
remember the area of a rectangle is given by:
[tex]\text{Area}_{rec}=\text{ length}\cdot width[/tex]then
let.
[tex]\begin{gathered} length=31^{\prime}\text{ } \\ \text{ width= }=5^{\prime}5^{\doubleprime} \end{gathered}[/tex]to operate , we need to have the same unit of measure, so we need to convert ft(') into inch(')
remember that
12 inches = 1 ft
hence
[tex]\begin{gathered} length=31^{\prime}\text{ }=31\text{ ft=31 ft(}\frac{12\text{ in}}{1\text{ ft}}\text{)=3}72\text{ inches} \\ \text{ width= }=5^{\prime}5^{\doubleprime}=5\text{ ft+5 in=5 ft(}\frac{12\text{ in}}{1\text{ ft}}\text{)}+\text{ 5 in=60 in+5 in=65 inches} \end{gathered}[/tex]now, replace in the formula to find teh area of the wall
[tex]\begin{gathered} \text{Area}_{rec}=\text{ length}\cdot width \\ A=372\text{ in}\cdot\text{ 65 in} \\ A=24180(in)^2 \end{gathered}[/tex]Area of the wall = 24180 squared inches
Step 2
now, we to find the area of each stoke ( also a rectangle)
then
Let
[tex]\begin{gathered} \text{length = 15 }\frac{1}{2}in \\ \text{width}=\text{ 6 }\frac{1}{2}\text{ in} \end{gathered}[/tex]to operate we need to convert the mixed numbers into improper fractions,
remember how to do that
[tex]a\frac{b}{c}=\frac{(a\cdot c)+b}{c}[/tex]therefore,
[tex]\begin{gathered} 15\text{ }\frac{1}{2}=\frac{(15\cdot2)+1}{2}=\frac{31}{2} \\ \text{and} \\ 6\frac{1}{2}=\frac{(6\cdot2)+1}{2}=\frac{13}{2} \end{gathered}[/tex]so
[tex]\begin{gathered} \text{length = }\frac{31}{2}in \\ \text{width}=\text{ }\frac{13}{2}\text{ in} \end{gathered}[/tex]now, let's replace in the formula to find the area of each stoke
[tex]\begin{gathered} \text{Area}_{rec}=\text{ length}\cdot width \\ A=\frac{31}{2}in\cdot\frac{13}{2}in \\ A=\frac{403}{4}=100.75\text{ squared inches} \\ A=100.75(in)^2 \end{gathered}[/tex]Area of echa stoke: 100.75 squared inches
Step 3
Finally, to get the number of stones that will take to build the wall, we need to divide the total area, by the area of one stoke
so
[tex]\text{ number of stokes required=}\frac{area\text{ of the wall}}{\text{area of each stoke}}[/tex]replace
[tex]\text{number of stokes required=}\frac{24180(in)^2}{100.75((in)^2}=240[/tex]hence
the answer is
240 stokes
I hope this helps you