100 envelopes cost you .70 what would 250 envelopes cost you

250/100 = 2.5
2.5*7 = 1.75
$1.75

Hope this helped!

1.75 is the answer

that's is the answer

Directly proportional: as one amount increases, another amount increases at the same rate.It's the relation between quantities whose ratio is constant.

In an inverse proportion, the two variables are inversely proportional to one another. One can write this equation as y = k/x, where K is the constant of proportionality that relates the two variable. In this equation as X increases, Y decreases.