GreenlightTestPrep wrote:
If \(\frac{5n}{4n - x} = 0.788^{-1}\), then \(\frac{x}{n} =\)
I created this question to test a certain fraction property that the GRE likes to test:
(a - b)/c = a/c - b/cThere's also
(a + b)/c = a/c + b/cGiven: 5n/(4n - x) = (0.788)^(-1)
Rewrite as: 5n/(4n - x) = 1/0.788
Flip each fraction: (4n-x)/5n = 0.788
Apply above
property: 4n/5n - x/5n = 0.788
Simplify: 4/5 - x/5n = 0.788
Simplify: 0.8 - x/5n = 0.788
So: x/5n = 0.012
Multiply both sides by 5 to get: x/n = 0.06
Rewrite as fraction: x/n = 6/100 = 3/50
Answer: 3/50