A15% tip represents the ratio 15 cents to 100 cents. why does this make 15% a unit-less factor?

Zoe placed colored blocks on a scale in science class. each block weighed 0.8 ounces. the total weight of all the colored blocks was 12.8 ounces. how many blocks did zoe place on the scale? write and solve an equation to find the answer.

Which ordered pair (c,d) is a solution to the given system of linear equations- c+2d=13 -9c-4d=-15

Convert 2000 swiss francs to dutch guilders