Let's break down this family age puzzle step-by-step to find out how many people are younger than D.

Determining Possible Ages

We are given that the family has seven members and their ages are distinct. The ages are arranged from highest to youngest, and the age difference between consecutively arranged persons is 3 years. The youngest person's age is 46.

This means the ages form an arithmetic progression with a common difference of 3. Starting from the youngest:

• Youngest age: 46
• Second youngest: $46 + 3 = 49$
• Third youngest: $49 + 3 = 52$
• Fourth youngest: $52 + 3 = 55$
• Fifth youngest: $55 + 3 = 58$
• Sixth youngest: $58 + 3 = 61$
• Oldest: $61 + 3 = 64$

So, the seven distinct ages are: 64, 61, 58, 55, 52, 49, 46.

Placing Family Members Based on Clues

Now, let's use the given clues to assign these ages to the family members (A, B, C, D, E, F, G).

• Clue 1: The age of B is 61.
  This places B at the second position from the oldest.
  Ages: 64, 61 (B), 58, 55, 52, 49, 46
• Clue 2: B is older than A.
  Since B is 61, A must be younger than 61. A's possible ages are 58, 55, 52, 49, or 46.
• Clue 3: A is older than E and D.
  This means A cannot be among the youngest three (52, 49, 46) because D and E must be younger than A. Therefore, A's possible ages are 58 or 55.
• Clue 4: A's age is not 55.
  Combining this with the previous clue, A's age must be 58.
  Ages: 64, 61 (B), 58 (A), 55, 52, 49, 46
• Clue 5: D's age is not 55.
  Also, A (58) is older than D. So D must be younger than 58. Possible ages for D are 55, 52, 49, 46. Since D's age is not 55, D's possible ages are 52, 49, or 46.
• Clue 6: E is younger than D.
  Also, E is not the youngest (age 46).
• Clue 7: The age of G is less than 52.
  Possible ages for G are 49 or 46.

Evaluating Possible Scenarios for D and E

Let's test the possible ages for D (52, 49, 46) based on the clues for D and E.

• Scenario 1: If D's age is 52.
  • A (58) > D (52). This fits.
  • E is younger than D (52) and not the youngest (46). So, E must be 49.
    Ages order: 64, 61(B), 58(A), 55, 52(D), 49(E), 46.
  • Now consider G. G's age is less than 52. Possible ages for G are 49 or 46. Since E is 49, G must be 46.
    Ages order: 64, 61(B), 58(A), 55, 52(D), 49(E), 46(G).
  • Let's check all conditions:
    • 7 members, distinct ages, diff=3: Yes (64, 61, 58, 55, 52, 49, 46)
    • E (49) not youngest (46): Yes.
    • E (49) younger than D (52): Yes.
    • D's age (52) is not 55: Yes.
    • B's age is 61: Yes.
    • B (61) older than A (58): Yes.
    • Youngest is 46: Yes.
    • G's age (46) is less than 52: Yes.
    • A (58) older than E (49): Yes.
    • A (58) older than D (52): Yes.
    • A's age (58) is not 55: Yes.
    This scenario is valid. The order is confirmed with D at age 52.
• Scenario 2: If D's age is 49.
  • A (58) > D (49). This fits.
  • E is younger than D (49) and not the youngest (46). This is impossible, as the only age younger than 49 is 46, which is stated as the youngest. There's no age left for E that is younger than 49 but older than 46.
  This scenario is invalid.
• Scenario 3: If D's age is 46.
  • A (58) > D (46). This fits.
  • E is younger than D (46). This is impossible, as 46 is the youngest age in the family.
  This scenario is invalid.

Final Arrangement and Answer

The only valid scenario places D at the age of 52. The ages from oldest to youngest are:

The question asks: How many person(s) is/are younger to D?

D's age is 52. The members younger than D are E (age 49) and G (age 46).

Therefore, there are Two persons younger than D.