Give the solver any two ratios pinned to any two moments and it runs the bracket method line by line. The first three cases are three different pairs of facts about the same two people — Vijay 10 and Radha 15 — so switching between them changes the work and not the answer. Keep an eye on the Difference tile.
2 : 3 today, 3 : 4 in five years
Vijay 10 · Radha 15 · gap 5
Each ratio is first person : second person, and the control beside it says which moment that ratio belongs to. Two facts at the same moment, or two facts with the same ratio, cannot pin anything down — try it and read the note.