In a certain code, MAXIMUM is written as 131249132113. How is TRAVEL written…

CONCEPT: In this letter-to-number coding, every letter of a word is replaced by its own position in the English alphabet, counting A = 1 up to Z = 26, and the word's code is formed by writing these position numbers one after another, in the same left-to-right order as the letters, with no separator between them.

First, confirm this rule against the example already given, MAXIMUM:

Concatenating these positions in the letters' order -- 13, 1, 24, 9, 13, 21, 13 -- reproduces 131249132113 exactly, so the rule is confirmed.

Now apply the same rule, letter by letter, to TRAVEL:

Concatenating these positions in order -- 20, 18, 1, 22, 5, 12 -- gives 2018122512.

CROSS-CHECK: T, R, V and L each sit at a two-digit position (10-26), while A and E sit at a single-digit position (1-9), so the code should have 2 + 2 + 1 + 2 + 1 + 2 = 10 digits -- and 2018122512 has exactly ten digits. Reading the string back in those same blocks -- 20 | 18 | 1 | 22 | 5 | 12 -- recovers T, R, A, V, E, L in order, with nothing dropped or merged.

So TRAVEL is written as 2018122512 in this code.