Systems word problems

Tyler is catering a banquet for 250 people. Each person will be served either a chicken dish that costs $5 each or a beef dish that costs $7 each. Tyler spent $1500. How many dishes of each type did Tyler serve?

The math club and the science club had fundraisers to buy supplies for a hospice. The math club spent $135 buying six cases of juice and one case of bottled water. The science club spent $110 buying four cases of juice and two

cases of bottled water. How much did a case of juice cost?

Michelle is making goodie bags for Christmas filled with chocolates and candy. Chocolates cost $2.50 per lb and candy costs $3.00 per lb. How many pounds of each did she purchase if she bought a total of 15 pounds and only spent $42?