Parker is planning to build a playhouse for his sister. The scaled model below gives the reduced measures for width and height. The width of the playhouse is 22 centimeters and the height is 10 centimeters.
Not drawn to scale

The yard space is large enough to have a playhouse that has a width of 3.5 meters. If Parker wants to keep the playhouse in proportion to the model, what cross multiplication of the proportion should he use to find the height?

Your vet has placed your pet on a diet. the diet is to contain at least 12 mg of fat and at least 14 mg of protein per serving. these requirements are to be obtained from two food sources. source a contains 2 mg of fat and 2 mg of protein per serving. source b contains 1 mg of fat and 3 mg of protein per serving. if source a sells for $1.28 per serving and source b sells for $1.12 per serving, how many servings of each type should be purchased to satisfy the requirements at minimal cost?