R = 10, T = 20
OK. Calculate the length of segment RT:
|RT| = |20 - 10| = |10| = 10
Divide |RT| into a ratio of 2:3
2 + 3 = 5
10 : 5 = 2
Therefore we have
|RS| = 2 · 2 = 4 and |ST| = 3 · 2 = 6 (4 + 6 = 10 CORRECT)
T = R + 4 and T = T - 6
T = 10 + 4 = 14; T = 20 - 6 = 14 CORRECT
Your answer is T = 14.