Christmas balls
On the Christmas tree, we put 21 Christmas balls of two colors. Eight of them were blue. How many Christmas balls were red?
Correct answer:

You need to know the following knowledge to solve this word math problem:
Related math problems and questions:
- Together 3331
The group has 12 red girls and 25 blue girls in costumes. How many of them can we put together a group of 6 girls so that the four girls have red outfits?
- Three colors
Find the probability that three balls of the same color will be drawn from fate with ten white, ten red, and ten blue balls.
- Arrangements 68764
We have two identical blue balls and two identical red balls. We arrange them in a row in all ways. How many different arrangements are there?
- Unmistakable 3609
We put 5 blue, 4 red, and 7 yellow balls in an unmistakable bag. Fero's task is to draw a yellow ball while blindfolded. How many marbles must Fero draw to be sure that a yellow marble will be among the ones drawn?
- Transparent 5345
Clay balls and several transparent glass balls spilled out of Peter's pouch. Color the balls one by one if you know that 1/6 were red, 3/8 were blue, 7/24 were green, and 1/12 were yellow. How many glasses did he have?
- Probability RGB
The bag has six red, five green, eight blue, and 11 yellow balls. What is the probability that we will pull out a green ball?
- Red balls
The bag has three red, 12 blue, and eight green balls. If we want the probability of pulling out the red balls to be 20%, how many red balls must we add to the bag?