BTGmoderatorLU wrote:Source: Manhattan Prep

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.

The OA is E.

So, there can be few arrangements. Two such as given below

1: GYR | GYR |GYR |GYR |GYR |GYR |GYR |GYR |

2: GYRGGGGGGGGGGGGGGGGGGGGG

Note that G not necessarily follows any tile.

Let's take each statement one by one.

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

Let's mark the color of times in the two arrangements.

1: GYR | GYR |GYR |GYR |GYR |GYR = 18th tile (not yellow) |GYR |GYR = 24th tile |

24th tile = Red

2: GYRGGGGGGGGGGGGGGG = 18th tile (not yellow) GGGGGG = 24th tile

24th tile = Green

No unique answer.

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

Let's take the following arrangements...

3: GYRGGGGGGGGGGGGGGG Y = 19th tile (not green) RGGGG = 24th tile

24th tile = Green

4: GYRGGGGGGGGGGGGGGG Y = 19th tile (not green) RGGYR = 24th tile

24th tile = Red

No unique answer.

Both the arrangements discussed above are applicable for both the statements tother. Thus, a unique answer is not possible. Insufficient.

The correct answer: E

Hope this helps!

-Jay
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