Answer :
Answer:
B. 18
Step-by-step explanation:
The 4 machines can produce x units in 6 days. This means they have a daily total rate of x/6 units per day.
Since the machines are similar and that they work at the same rate, this means that the individual rates of each machine would be x/6/4 = x/24 units per day.
Now we are looking at producing 3x units in 4 days. This means that we want to produce 3x/4 units in a single day. Now, since each machine would work at a rate of x/24, we need to know the number of machines we need. To know this number, we simply divide what is to be achieved by the individual rate:
This is 3x/4 divided by x/24. This mathematically means 3x/4 * 24/x = 18 machines