A meat market combines ground beef and ground pork in a single package for meat loaf. The ground beef is $75\%$ lean $(75\%$ lean, $25\%$ fat$)$ and costs the market $$0\mathrm{.}80$ per pound. The ground pork is $60\%$ lean and costs the market $$0\mathrm{.}65$ per pound.

The meat loaf must be at least $70\%$ lean. If the market wants to use at least $50$ lb of its available pork, but no more than $200$ Ib of its available ground beef, how much ground beef should be mixed with ground pork so that the cost is minimized?

The meat market should combine Blank $1$ pounds or ground beef and Blank $2$ pounds of ground pork $($round your results to the nearest integer$).$