Read the information carefully and answer the questions given below: Seven…
2025
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?
- A.
E
- B.
B
- C.
G
- D.
D
- E.
None
Attempted by 3 students.
Show answer & explanation
Correct answer: B
Concept
In an age-arrangement puzzle, first convert every birth year to an age using the fixed base year (age = base year − birth year). Then translate each clue into an arithmetic or ordering condition on those ages, and fix the people one constraint at a time, starting with the most restrictive clues (divisibility and exact-sum clues narrow the options fastest).
Setting up the ages
With base year 2025, the seven available ages are:
1947 → 78
1959 → 66
1964 → 61
1973 → 52
1978 → 47
1988 → 37
2001 → 24
Applying the clues
"G's age is divisible by 6": among the ages only 78, 66 and 24 are multiples of 6, so G is 78, 66 or 24.
"Sum of the ages of C and F equals the age of D": the only triple from the list with this property is 24 + 37 = 61, so {C, F} take 24 and 37 (in some order) and D = 61.
"A is just older than F" (A is the immediate next age above F): F is 24 or 37. If F = 24 then C = 37, and the age just above 24 is 37 — but 37 is already taken by C, so A could not occupy it; this case is impossible. Hence F = 37, the age just above 37 is 47, so A = 47, and therefore C = 24.
"The total age of A and G is a prime number": A = 47, so 47 + G must be prime. Testing the remaining multiples of 6: G = 78 gives 125 (= 5 × 25, not prime); G = 66 gives 113 (prime). So G = 66. (G = 24 is already taken by C.)
"Sum of the ages of B and A is divisible by 5": A = 47, so B must complete a multiple of 5. Of the ages still free (78 and 52), 78 + 47 = 125 is divisible by 5 while 52 + 47 = 99 is not, so B = 78. The last remaining age, 52, goes to E.
Final ages
A = 47 (1978)
B = 78 (1947)
C = 24 (2001)
D = 61 (1964)
E = 52 (1973)
F = 37 (1988)
G = 66 (1959)
Cross-check and result
Verify every clue against these ages: 24 + 37 = 61 (C + F = D); 66 is divisible by 6 (G); 47 + 66 = 113 is prime (A + G); 47 is the age just above 37 (A just older than F); 78 + 47 = 125 is divisible by 5 (B + A). All clues hold. The largest age is 78, so the oldest person is B.