In a certain code language, 'CHILD' is written as '6169248' and 'GUEST' is written as '142153840'. How will 'BOOK' be written in that language?

Let's examine the coding pattern using the alphabetical positions (A = 1, B = 2, ..., Z = 26) and their reverse positional values (A = 26, B = 25, ..., Z = 1):
For 'CHILD':

Consonants are multiplied by 2:

C = 3 →3×2=6

H = 8 →8×2=16

L = 12 →12×2=24

D = 4 →4×2=8

Vowels take their standard position value:

I = 9
Combining them: 6, 16, 9, 24, 8 → '6169248'.

For 'GUEST':

G = 7 (Consonant) →7×2=14

U = 21 (Vowel) →21

E = 5 (Vowel) →5

S = 19 (Consonant) →19×2=38

T = 20 (Consonant) →20×2=40
Combining them: 14, 21, 5, 38, 40 → '142153840'.

Following the same logic for 'BOOK':

B = 2 (Consonant) →2×2=4

O = 15 (Vowel) →15

O = 15 (Vowel) →15

K = 11 (Consonant) →11×2=22

Combining the values gives: 4, 15, 15, 22 → '4151522'.