In a certain chemical, the ratio of zinc to copper is 3 to 13. A jar of the chemical contains 299 grams of copper. How many grams of zinc does it contain?

Can someone me out here and the tell me the greatest common factor

The first floor of marcus’ house is 1,440 square feet. he will cover 1,033 square feet with wood and the rest with tile. a box of tiles will cover 11 square feet. how many boxes of tile does marcus need to buy to cover the floor?

The difference of three and the reciprocal of a number is equal to the quotient of 20 and the number. find the number.