Final answer:
To determine when Tom and David will get their hair cut on the same day again, we find the Least Common Multiple (LCM) of their haircut frequencies. The LCM of 4 and 6 is 12, so they will next have their hair cut on the same day in 12 weeks (c).
Step-by-step explanation:
The question involves finding a common multiple, which in this context is the least number of weeks after which both Tom and David will get their hair cut on the same day again.
Since Tom gets his hair cut every 4 weeks and David every 6 weeks, we need to find the Least Common Multiple (LCM) of 4 and 6. The multiples of 4 are 4, 8, 12, 16, 20, 24, and so on, while the multiples of 6 are 6, 12, 18, 24, and so on. The first common multiple is 12, which means they will both get their hair cuts again on the same day in 12 weeks.
Therefore, the correct answer is (c) 12 weeks. This is an example of a real-life application of LCM in scheduling.