Answer: The answer is 3 months.
Step-by-step explanation: Given that Tom has a collection of 30 CD's and Nita has a collection of 18 CD's. Tom is adding 1 CD a month to his collection while Nita is adding 5 CD's a month to her collection. We are to find the number of months after which both will have the same number of D's.
Let 'x' be the required number of months. Then, we will have

Therefore, the number of months is 3.
Thus, the answer is 3 months.