When we have a midsegment like that we get similar triangles UTV ~ USR and the scale factor is 2.
So RS=2 TV and the geometry part is over and now it's algebra practice.
z + 67 = 2(z + 20)
z + 67 = 2z + 40
67-40 = 2z - z
27 = z
RS=z+67 = 94
Answer: 94
Check: TV=20=47
2×47 = 94, good