A.

from the question,
the total speed for the pedestrian is
40km and the total time is 10hr
substitute them in the formula, we get

speed = 4km/hr
B. 10hrs - 6hrs = 4hours
C. BC is deacceleration = -dv/dt
CD is constant acceleration = dt = 0
Answer:
2%
Step-by-step explanation:
20% takes 10 years to decay
To find per year decay, we divide the percentage by the number of years, so we get unit rate of years {per year]. Thus we have:
20%/10 = 2% per year
It's that simple.
Hence, the percentage by which the substance decays each year is 2%
Answer:
The first one is C and I don't know what the other one is
Bro, Kilo means thousand times,