Question 1119068
The denominator is 28C4, choosing 4 apartments at random from 28.
The numerator is 20C4, choosing only the two bedroom apartments.  The other part of the numerator would be the missing numbers 8C0, but 8C0=1, so it can be ignored.
20C4/28C4=0.2366.
The second will have numerator 20C2*8C2 with the same denominator.  Notice that the pre-Cs in the numerator add up to 28 and the post-Cs add up to 4.
probability is 0.2598.
Can check by looking at the other three possibilities, 0,1,3 are two bedroom.
Those probabilities are 0.0547 with numerator 20C1*8C3
and 0.0034 with numerator 20C0*8C4
0.4454 with numerator 20C3*8C1.
Those add to 1.