I believe the answer is 4k + 11
Convert the mixed number <span>21 <span>2/3</span></span><span> into an </span><span>improper fraction.
</span>15⋅<span>65/3
</span><span>Cancel 3 and 15.
</span><span>5⋅65
</span>Multiply 5<span> by </span>65<span> to get </span><span>325.
</span>325
Answer:
325
<span>Because the town was built above sheer cliffs that were heavily defended by artillery.</span>