what is the greatest common factor of 17 and 51

The greatest common factor of 17 and 51 is 17.

what is the greatest common factor of 90 and 72

The greatest common factor of 90 and 72 is 18.

what is the greatest common factor of 100 and 68

The greatest common factor of 100 and 68 is 4.

so four bloons and 4 stickers?

No, the concept of "four bloons and four stickers" does not apply to the greatest common factor. The greatest common factor is a mathematical concept used to determine the largest number that divides evenly into two given numbers. It does not relate to physical objects or stickers.