Answer
See below.
Work Step by Step
Our two equations in this case (if the number of short sleeved T-shirts is $x$ and long-sleeved is $y$): $8x+10y=3715\\-88x-110y=-40865$ and $11x+16y=6160\\88x+128y=49280$
Then adding the two changed versions of equations we get: $18y=8335\\y\approx 463$.
But then $x$ is negative, so this is not a realistic case.
