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Last Updated on May 10, 2023
GMAT OFFICIAL GUIDE PS
Solution:
We are given that 4 machines can produce a total of x units in 6 days. Since rate = work/time, the rate of the 4 machines is x/6. We need to determine how many machines, working at the same rate, can produce 3x units of product P in 4 days. Thus, we need to determine how many machines are needed for a rate of 3x/4.
Since we know that all the machines are working at an identical constant rate, we can create a proportion to determine the number of machines necessary for a rate of 3x/4. The proportion is as follows:
“4 machines are to a rate of x/6 as n machines are to a rate of 3x/4.”
4/(x/6) = n/(3x/4)
24/x = 4n/(3x)
When we cross multiply, we obtain:
72x = 4xn
18 = n
Answer: B
