Final answer:
There are 62 red disks.
Step-by-step explanation:
Let's solve this problem step-by-step:
Let the number of green disks be x. So, the number of red disks would be x + 30 and the number of blue disks would be x - 21.
According to the given information, the total number of disks is 105. Therefore, we can write the equation:
x + (x + 30) + (x - 21) = 105
Now, solve the equation through the steps:
- Combine like terms: 3x + 9 = 105
- Subtract 9 from both sides: 3x = 96
- Divide both sides by 3: x = 32
Therefore, the number of green disks is 32 and the number of red disks is 32 + 30 = 62.