The total rate, r (in mol/s) at which a population of calcium pumps remove calcium from a

The total rate, r (in µmol/s) at which a population of calcium pumps remove calcium from a cell is given by the formula r = dA r¯
, where d (in µmol µm−2 ) is the density of the pumps, A (in µm2 ) is the area of the cell membrane, and r¯ (in s) is the time constant of a single pump.
Suppose we make the following measurements:
d = 0.10

µmol µm

−2

, A = 2.0

× 101

µm 2

, r¯ = 0.10 s.

a. Show that the units are the same on both sides of the equation.

b. What is the relative uncertainty in r?

c. What is the absolute uncertainty in r?