[tex]2 \frac{5}{6}*2= \frac{17}{6}* \frac{2}{1} = \frac{17}{3}= 5\frac{2}{3} [/tex]
[tex]5 \frac{2}{3}: \frac{1}{4}= \frac{17}{3}* \frac{4}{1}= \frac{68}{3} =22 \frac{2}{3} [/tex]
23 stones will be needed
(you have to round up, since you can't have a fraction of a stone)
