What was the velocity of the object (in km/min) at point D?

"i have always loved contemporary art and made it a general goal to work within the field. after a few nonprofit internships at museums and galleries, i decided to try the for-profit art world and was offered a job as the ad assistant at the magazine. i much prefer the pace of the for-profit art community and have stayed with the company for three years, with a promotion to an account manager last spring."

i just did this and got a 100.

answer: a) y=-8x+5

a) m= -8

b) m= -2

c) m= 7

d) m= 6