To solve this problem, let's introduce some variables and set up equations based on the information given:

1. Define the Variables:
   Let $B$ be Brian's current age, and $C$ be Caroline's current age.

2. Translate the Given Information into Equations:

   • Brian is three times as old as Caroline:
     $B = 3C$

   • Four years from now, Brian will be twice as old as Caroline:
     $B + 4 = 2(C + 4)$

3. Set Up the Equations:
   We now have the following two equations: $B = 3C$ $B + 4 = 2(C + 4)$

4. Substitute and Solve:
   Substitute $B = 3C$ into the second equation: $3C + 4 = 2(C + 4)$

   Expand and simplify the equation: $3C + 4 = 2C + 8$

   Subtract $2C$ from both sides: $C + 4 = 8$

   Subtract 4 from both sides: $C = 4$

5. Find Brian's Age:
   Using the first equation $B = 3C$: $B = 3 \times 4 = 12$

Conclusion:

• Caroline is currently 4 years old.
• Brian is currently 12 years old.

Verification:

• Four years from now, Caroline will be $4 + 4 = 8$ years old.
• Four years from now, Brian will be $12 + 4 = 16$ years old.
• Indeed, 16 is twice 8, so the solution is correct.

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Would you like further details or have any questions?

Here are five related questions to consider:

1. How old will Caroline be in 10 years?
2. How old was Brian when Caroline was born?
3. If the age difference remains the same, how old will Brian be when Caroline turns 20?
4. What is the sum of Brian and Caroline's current ages?
5. If another person, David, is 5 years older than Brian, how old is David?

Tip: When dealing with age-related problems, always relate the ages using variables and then set up equations based on given conditions to find the solution.