CCommunity
Consider the numerical value of letters as per the English alphabetical series.
The pattern followed here is:
C + 4 = G
A + 4 = E
R + 4 = V
R + 4 = V
O + 4 = S
T + 4 = X
Same Pattern will be followed for APPLE.
A + 4 = E
P + 4 = T
P + 4 = T
L + 4 = P
E + 4 = I
Hence, APPLE will be coded as ETTPI.