How many decimal places come in the answers to the following additions and subtractions?

a) [[$\text{0.0024} + \text{0.2} - \text{0.00075} $]]


b) [[$\text{11.236} - \text{2,66} + \text{6.0002} $]]


c) [[$-\text{0.0013} + \text{3.141} - \text{12.2}$]]