Answer
a. 0.01 m
b. the greatest possible error is $$0.005 \ m.$$
Work Step by Step
For the measurement $6.05~m$, we have
a. The precision is $0.01~m$ (since the last digit $5$ is at $0.01$ precision).
b. The greatest possible error is one-half the precision:
$$0.5\cdot 0.01 \ m=0.005 \ m.$$
