What is the last digit of

A. 5
B. 3
C. 7
D.6
E. 9

At the many chips cookie company they are serious about the number of chocolate chips in their cookies they claim that each cookie hasn't c chips. if their claim is true there will be 200 chips in 10 cookies

The line containing the midpoints of the legs of right triangle abc where a(-5,5), b(1, 1), and c(3, 4) are the vertices.

Which shows the correct solution of the equation 1/2a+2/3b=50, when b=30?