C.
12/30=0.4
You should really learn how to do probabilities. They don't go away after like the sixth grade.
Answer:
the largest is 620cm the next is 4.4 dam and the smallest is 0.52 km
4(r)^x=y
4(r)^(1)=2
r=1/2
y=4*(1/2)^x
The equation of the tangent line can be found using slope formula and fact that slope = dy/dx.

where (x0,y0) is point A ---> (0,-1)
Then rearrange equation into slope-intercept form:

Finally sub in x=0 into dy/dx to get slope at the point (0,-1)
C because if you divide the angle minus the feet you get 120