Final answer:
The least common multiple of 9 and 12 is 36 months.
Step-by-step explanation:
To find the least number of months that will pass before the two CDs mature at the same time, we need to find the least common multiple (LCM) of 9 and 12.
- Find the prime factors of both numbers. For 9: 3 x 3. For 12: 2 x 2 x 3.
- Take the highest power of each prime factor: 3^2 x 2^2 = 36.
Therefore, the least number of months that will pass before the two CDs mature at the same time is 36 months.