A median cuts a leg of a triangle in half. So for instance, PF being a median means that DP and PE are congruent and have the same length. Consequently, each component triangle (that is, ∆DPC, ∆EPC, ∆EQC, etc) all have the same area.
If A is the area of ∆PCE, then the area of ∆PFE is 3A.
Take PF = 24 to be the base of ∆PFE, and take PC to be the base of ∆PCE. The area of any triangle is equal to 1/2 times the base times the height. But ∆PFE and ∆PCE share the same height (you can see this by dropping an altitude from the vertex E down to the line containing PF), so PC is 1/3 the length of PF, so FC must be 2/3 the length of PF.
So FC has length 2/3 × 24 = 16.