Both sentences are masked here, which is how the harder Model 2 questions are printed. The solver strips each mask to a ratio, then solves the plain problem underneath. All four cases below describe Vijay at 15 and his father at 25 — eight different masks, one pair of ages.
A is 3/5 of B; in 5 years A will be 2/3 of B
Vijay 15 · father 25 · ratio 3 : 5
Try changing only the first control between the first two cases: “3/5 of” and “60% of” are the same sentence, so the ages do not move. Then pick two masks that hide the same ratio and read why the solver refuses.