An alternate approach for combining the two statements:
Let \(O\) = the amount of oats fed to Piglet A and \(B\) = the amount of barley fed to Piglet A.
Since the \(O\) pounds of oats fed to Piglet A constitute 1/4 of all the oats, the total amount of oats = \(4O\)
Since the \(B\) pounds of barley fed to Piglet A constitute 1/6 of all the barley, the total amount of barley = \(6B\)
Thus, the total amount of feed \(= 4O+6B\)
Since each piglet receives the same amount of feed, the amount of feed per piglet = the amount fed to Piglet A = \(O+B\)
Thus:
Number of piglets = \(\frac{total-feed}{feed-per-piglet} = \frac{4O+6B}{O+B}\)
The resulting expression represents the WEIGHTED AVERAGE for \(O\) and \(B\).
If \(O=100\) and \(B=0\) so that the average is weighted completely toward \(O\), we get:
weighted average = \(\frac{4O+6B}{O+B}= \frac{400}{100} = 4\)
If \(O=0\) and \(B=100\) so that the average is weighted completely toward B, we get:
weighted average \(= \frac{4O+6B}{O+B} = \frac{600}{100} = 6\)
In the posted problem, O and B must be positive values, since the feed contains both oats and barley.
As a result, the weighted average cannot actually be equal to 4 or 6 but must be BETWEEN these two values.
Since 5 is the only integer between 4 and 6, the number of piglets = 5.
SUFFICIENT.