Carcass wrote:
If \(2 < x < 5\) and \(7 < y < 10\), then \(\frac{1}{(y - x)}\) is between
(A) 1/8 and 1
(B) 1/4 and 1
(C) 1/5 and 2/3
(D) 1/8 and 1/2
(E) 1/2 and 2/3
The endpoints for y are 7 and 10.
The endpoints for x are 2 and 5.
To determine the range of y-x, calculate y-x using EVERY POSSIBLE COMBINATION OF ENDPOINTS:
7-2 = 5
7-5 = 2
10-2 = 8
10-5 = 5
The smallest result is 2, and the greatest result is 8.
Thus:
2 < y-x < 8
Implication:
The endpoints for \(\frac{1}{y-x}\) are \(\frac{1}{2}\) and \(\frac{1}{8}\)