Answer all questions in section A and three (3) from section B

The dimension is given as $50.00 + 0.05 \text{mm}$.
This indicates a nominal size of $50.00 \text{mm}$.
The upper limit (maximum permissible size) is $50.00 + 0.05 = 50.05 \text{mm}$.
Since no lower deviation is specified, the lower limit (minimum permissible size) is assumed to be the nominal size, which is $50.00 \text{mm}$.

Tolerance is the difference between the maximum permissible size and the minimum permissible size.

The tolerance is $\text{0.05 mm}$.