If Priya is ready to board a train at 10:25 am from station T, then when is the earliest that she can reach station S?
Answer: A
Priya can go from T to S via R or V.
Case 1: T – R – S
The first train to depart T will be at (6 am + 9 + 2 + 2 =) 6:13 am.
∴ Now a train will depart T every 15 minutes, hence the train which Priya can catch for T → R is at 10:28.
Time taken to reach R = 12 + 3 = 15 mins.
∴ Priya reaches R at 10:43 am.
The first train to depart R will be at (6 am + 8 + 3 + 2 =) 6:13 am.
∴ Now a train will depart R every 10 minutes, hence the train which Priya can catch for R → S is at 10:43 itself.
Time taken to reach S = 20 + 9 = 29 mins.
∴ Priya reaches S at 11:12 am.
Case 2: T – S – R
The first train to depart T will be at (6 am + 8 + 3 + 2 =) 6:13 am.
∴ Now a train will depart T every 10 minutes, hence the train which Priya can catch for T → V is at 10:33 itself.
Now time taken from T → V is 29 mins and time taken from V → S is 15 mins.
Even if Priya does not have to wait at V she can S latest by 10:33 am + 29 + 15 = 11:17 am.
∴ Priya can reach S latest by 11:12 am.
Hence, option (a).