Fellow exo-l, I hope this is what you meant by your question, it's a bit vague given that your question q = 50k1/3l1/2. So, I assumed that's what you meant. If not, please tell me and I can edit it again.
[tex]q = 50k (\frac{1}{3}l)( \frac{1}{2} ) \\ q = (50 \times 8)( \frac{1}{3} \times 4)( \frac{1}{2} ) \\ q = 400 \times \frac{4}{3} \times \frac{1}{2}[/tex]
[tex]q = 400 \times \frac{4}{3} \times \frac{1}{2} \\ q = 400 \times \frac{4}{6} \\ q = 266 \frac{2}{3} [/tex]
A: 267 donuts can be produced.
Hope this helps. - M