So, the bag weights 11\(\frac{1}{2}\), that is 11.5,, and also that is \(\frac{11*2+1}{2} = \frac{23}{2}\) correct?
I changed it into an improper fraction, because the division will be easier later.
A serving is \(\frac{3}{4}\). So what we need to do is the divide the weight of the bag, that is \(\frac{23}{2}\) by the weight of the serving, that is \(\frac{3}{4}\).
a division by fraction is a multiplication by its inverse, like this:
\(\frac{23}{2}\)\(\frac{4}{3}\)
now we can simplify: the denominator of the first and the nominator of second are multilications of 2:
\(\frac{23}{1}\)\(\frac{2}{3}= \frac{46}{3} \frac{1}{3}\)
so there are 15 servings and a little will be left over.