motion2020 wrote:
If \(x\) is the sum of the reciprocals of the consecutive integers from 51 to 60, inclusive and \(y\) is the sum of the reciprocals of the consecutive integers from 61 to 70, inclusive, which of the following is correct?
I. \(\frac{1}{x} > 6\)
II. \(\frac{1}{y} > 7\)
III. \(\frac{1}{y} > \frac{1}{x}\)
Given \(x = \frac{1}{51} + \frac{1}{52} + .... + \frac{1}{60}\)
Since there are 10 integers, minimum is \(\frac{1}{60}\) and maximum is \(\frac{1}{51}\), so the value of x lies between \(\frac{10}{51} > x > \frac{10}{60}\) and taking inverse \(\frac{51}{10} < \frac{1}{x} < \frac{60}{10}\)
which translates to \(5.1 < \frac{1}{x} < 6\)
Similarly for y, \( 6.1 < \frac{1}{y} < 7\)
So from the choices, only III is true.