Perth Mining Company operates 2 mines for objective of extracting gold and silver. Saddle mine costs $14,000/day to operate and it yields 50 oz of gold and 300 oz of silver each day. Horseshoe Mine costs $16,000/day to operate and it yields 75 oz of of gold and 1000 oz of silver each day. Company management has set the target of at least 650 oz of gold and 18,000 oz of silver. How many days must every mine be operated so that target can be met at the minimum cost?