Traditional Culture Encyclopedia - The 24 Solar Terms - On Children's Day, students bought red, yellow and blue balloons to decorate the classroom, and hung them in the order of 3 red balls, 4 yellow balls and 5 blue balls.

On Children's Day, students bought red, yellow and blue balloons to decorate the classroom, and hung them in the order of 3 red balls, 4 yellow balls and 5 blue balls.

( 1)67÷ 12=5…7,

So the 67th balloon is the 7th balloon in the 6th cycle, which is the same color as the 7th balloon in the 1st cycle, and it is yellow.

(2)80÷ 12=6…8,

So the number of yellow balloons is 7×4=28 (pieces),

Answer: The 67th balloon is yellow. There are 28 yellow balloons in the first 80 balloons.

Therefore, the answer is: Huang; 28.