Five friends A, B, C, D, and E go on a trip together. Each of them likes at least one of the following three activities: Countryside Sightseeing, Shopping, and Adventure Sports such that:
- No two friends like exactly the same set of activities.
- A, B and E like exactly two activities each.
- D likes only Countryside Sightseeing.
- C likes more number of activities compared to D.
The number of friends who like both Shopping and Adventure Sports is ___
The Setup: This is a classic Logical Reasoning/Arrangements puzzle (IPMAT Indore vibes). Think of it as assigning unique loadouts to a 5-player squad from a pool of 3 perks (Countryside Sightseeing, Shopping, Adventure Sports). The golden rule here is the "no copycats" policy—every friend must have a totally unique combination of activities.
Step 1: Analyze the NPCs (D and C).
The prompt states D is a one-trick pony, only liking Countryside Sightseeing (CS). So, D's loadout size is exactly 1.
The rules also state C likes *more* activities than D. Since the max activities available is 3, C's loadout size must be either 2 or 3.
Step 2: Distribute the Duo Loadouts (A, B, E).
We are told A, B, and E each like *exactly* two activities. Let's calculate the total possible 2-activity combos from our pool of 3 (CS, Shopping=Sh, Adventure Sports=AS).
Using combinations:
The only possible duo sets are {CS, Sh}, {CS, AS}, and {Sh, AS}.
Step 3: Apply the "No Copycats" Rule.
Since no two friends can have the exact same set of activities, A, B, and E must each claim exactly one of these three unique duo combinations. All three 2-activity loadouts are now permanently locked and taken by this trio.
Step 4: Lock in C's Loadout.
Let's check back on C. We established C needs 2 or 3 activities. But wait—all the 2-activity slots are already hogged by A, B, and E! If C took a 2-activity set, they'd duplicate someone else's set, failing the vibe check (violating the main rule). Thus, C is forced to take the only remaining unique loadout size greater than 1: all 3 activities {CS, Sh, AS}. C is literally doing the 100% completionist run.
Step 5: Visualize the Final Roster.
Let's drop all this intel into a matrix to see exactly who is doing what.
| Friend | CS | Sh | AS |
|---|---|---|---|
| D | ✓ | — | — |
| One of A/B/E | ✓ | ✓ | — |
| One of A/B/E | ✓ | — | ✓ |
| One of A/B/E | — | ✓ | ✓ |
| C | ✓ | ✓ | ✓ |
From the table, look at the Sh and AS columns to see who is running the dual Shopping/Adventure Sports build. We count the rows where both show a ✓.
That's exactly the third A/B/E row and C. Total = 2.
Final Answer: 2