For the first solution, start by calculating the number of moles of NaCl in 1.95g. n=m/M= 1.95g / 58.44g/mol = 0.033mol.

0.033mol per 250mL of water, is the same as 0.033 x 4 = 0.133 mol per litre of water.

So the molality is 0.133 M.

'milli' is 10^-3. For example, a millimeter is 1/1000 (which is 10^-3) of a meter. So the millimolality of the solution will be 133 mM. Are you following?

osmolality is slightly more complex. It takes into account that a molecule may dissociate (split apart) in solution.

For the first solution, the milliosmolality is simply the millimolality (133mM) multiplied by 2 (since NaCl dissociates into 2 ions in solution - Na+ and Cl-).

Glucose however does not dissociate, so in the case of solution 2 the millimolality and milliosmolality will be the same.