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.
GYR is the initial order.
S1: 18th is not yellow so its either G or Yellow. Insuff. We can't determine what the 24th tile is from this.
S2: 19th is either R or Y. Insuff. we can't determine the 24th from this.
1&2: it could be GGGGGGGGGGGGGGGGGGYRGGGG Could be Green.
There is no constraint for G. I.E. nothing has to precede the green tile.