Data Sufficiency

In a single row of yellow, green and red colored tiles, every red tile is preceded immediately by a yellow tile and every yellow tile is preceded immediately by a green tile. What color is the 24th tile in the row?

(1) The 18th tile in the row is not yellow.

(2) The 19th tile in the row is not green.

Alright, this is a tricky and time consuming one

R = Red
Y = Yellow
G = Green

Sequence: R, Y, G

Stmt 1) The 18th tile in the row is not yellow.
Two possibilities:

A) 18 19 20 21 22 23 24
----G R Y G R Y G

B) 18 19 20 21 22 23 24
----R Y G R Y G R

Hence not sufficient

Stmt 2) The 19th tile in the row is not green.
Two possibilities:

A) 18 19 20 21 22 23 24
---- R Y G R Y G R

B) 18 19 20 21 22 23 24
---- G R Y G R Y G

Hence stmt 2 not sufficient as well.

Combining both statements:

18 Not Yellow and 19 not Green
Two possibilities, again:

A) 18 19 20 21 22 23 24
---- R Y G R Y G R

B) 18 19 20 21 22 23 24
---- G R Y G R Y G

Hence answer is E.

What do you understand with preceded, I set this order GYR - R is preceded by yellow and yellow is preceded by Green.

Another imp. thing which is not there in question is which tile preceed green; means RYGGGGGGGGGGGGG is also a valid tile arrangement.
Keeping this is mind, E is the only valid answer.

My bad.
Thanks for correcting!

OA E

shouldnt the answer be C??
as it says preceded the sequence would be GYRGYR
as 19th cannot be G, combining with (A) we get 18th as G and 19th as Y