21 incorrect

Part of 2019 India PRMO

Problems(1)

PRMO 2019 Leg 2 P21 the incorrect problem, show why

Source:

Consider the set

E

of all positive integers

n

such that when divided by

9,10,11

respectively, the remainders(in that order) are all

>1

and form a non constant geometric progression. If

N

is the largest element of

E

, find the sum of digits of

E

sum of digitsnumber theoryremainder