Which proportion could be used to express 18/20 as a percent

Which of the fallowing best completes the sequence 12,8,5, a) 1 b) 2 c)4 d)0

Create and solve a linear equation that represents the model, where squares and triangles are shown evenly balanced on a balance beam. assume the weight of a square is 1 unit and the weight of a triangle is unknown.

How many $20 bills do you need to have to make $280