Clues

1. Four tasks P, Q, R, and S are scheduled from 9 AM to 12 PM, one per hour.
2. P is scheduled before Q.
3. R is scheduled immediately after P.
4. S is at 12 PM.

Question

At what time is P scheduled?

Answer

P is scheduled at 9 AM.

Solution

1. S is fixed at 12 PM.
2. P-R is a consecutive block, with Q after P.
3. P cannot be 10 AM because Q would need the 12 PM slot, which is occupied by S.
4. Therefore P is at 9 AM, R is at 10 AM, and Q is at 11 AM.