Calculate the values for problems a) and c) based on the provided arithmetic expressions.

$$-16 + 19 = 3$$

The final answer for a) is:

$$\boxed{3}$$

First, multiply 70 by 40:

$$70 \times 40 = 2800$$

The expression becomes:

$$2800 \div 8 - 186$$

$$2800 \div 8 = 350$$

The expression becomes:

$$350 - 186$$

$$350 - 186 = 164$$

The final answer for c) is:

$$\boxed{164}$$