Read the information carefully and answer the questions given below:

Seven persons A, B, C, D, E, F and G were born on seven different years i.e., 1947, 1959, 1964, 1973, 1978, 1988 and 2001 on the same month and same date. (Base year is considered as 2025 for age calculation). The sum of the ages of C and F is equal to the age of D. G’s age is divisible by 6. The total age of A and G is a prime number. A is just older than F. The sum of the age of B and A is divisible by 5.

Who among the following is the oldest person?

To solve this puzzle, we first calculate the age of each person based on their birth year, using 2025 as the base year:

- Born in 1947: $2025-1947=78$ years old
- Born in 1959: $2025-1959=66$ years old
- Born in 1964: $2025-1964=61$ years old
- Born in 1973: $2025-1973=52$ years old
- Born in 1978: $2025-1978=47$ years old
- Born in 1988: $2025-1988=37$ years old
- Born in 2001: $2025-2001=24$ years old

The set of ages is: 78, 66, 61, 52, 47, 37, 24.

Step 1: Find the ages of C, F, and D.
We are given that the sum of the ages of C and F is equal to the age of D ($C+F=D$). Let's check the combinations of ages:
$24+37=61$
This is the only valid combination from our list. Therefore, D is 61 years old, and C and F are 24 and 37 in some order.

Step 2: Find the ages of A and F.
We are given that A is just older than F. This means A's birth year is the one immediately preceding F's birth year in the list.
If F's age were 24 (born in 2001), the person just older than F would be born in 1988 (37 years old). But 37 is the age of C, which would cause a conflict.
Thus, F's age must be 37 (born in 1988), which means C's age is 24 (born in 2001).
The birth year just before 1988 is 1978. Therefore, A is born in 1978, making A's age 47.

Step 3: Determine G's age.
We are given that G's age is divisible by 6. The remaining ages are 78, 66, and 52. Among these, 78 and 66 are divisible by 6.
We are also given that the total age of A and G is a prime number.
If G is 78: $A+G=47+78=125$ (not a prime number, as it is divisible by 5).
If G is 66: $A+G=47+66=113$ (which is a prime number).
Therefore, G is 66 years old.

Step 4: Determine the remaining ages.
The remaining ages to assign are 78 and 52 for B and E.
We are given that the sum of the ages of B and A is divisible by 5.
If B is 78: $B+A=78+47=125$ (divisible by 5).
If B is 52: $B+A=52+47=99$ (not divisible by 5).
Therefore, B's age is 78 and E's age is 52.

The final mapping of ages is:
- B: 78 (born in 1947)
- G: 66 (born in 1959)
- D: 61 (born in 1964)
- E: 52 (born in 1973)
- A: 47 (born in 1978)
- F: 37 (born in 1988)
- C: 24 (born in 2001)

The oldest person is B (78 years old, born in 1947).