What is the tenth letter in the following letter sequence? B, B, C, D, F, I,…

Concept

In a letter series, first convert each letter to its alphabet position, taking A = 1, B = 2, …, Z = 26.

When a resulting alphabet position exceeds 26, continue cyclically from A. The jumps here follow consecutive Fibonacci numbers, in which each new number is the sum of the previous two.

Application

1. The given positions are B = 2, B = 2, C = 3, D = 4, F = 6, I = 9, N = 14, and V = 22.

2. Their successive jumps are 0, 1, 1, 2, 3, 5, and 8. These are consecutive Fibonacci jumps, so the next two jumps are 13 and 21.

3. For the ninth letter, move 13 places from V: 22 + 13 = 35, and 35 − 26 = 9, which is I.

4. For the tenth letter, move 21 places from I: 9 + 21 = 30, and 30 − 26 = 4, which is D.

Cross-check

Starting from V, the two required cyclic moves are +13 to I and then +21 to D; both continue the same Fibonacci-jump rule.

Result

Therefore, the tenth letter is D.