If $\frac{a}{b + c}, \frac{b}{c + a}, \frac{c}{a + b}$ are in $H.P.$,then $a, b, c$ are in

The fifth term of the $H.P.$,$2, 2\frac{1}{2}, 3\frac{1}{3}, \dots$ will be

If $p, q, r$ are in harmonic progression and $p$ and $r$ are distinct and have the same sign,then what is the nature of the roots of the equation $px^2 + 2qx + r = 0$?

If $\frac{1}{b - a} + \frac{1}{b - c} = \frac{1}{a} + \frac{1}{c}$,then $a, b, c$ are in

If the $p^{th}$ term of a harmonic progression is $qr$ and the $q^{th}$ term is $pr$,then what is its $r^{th}$ term?

If ${x^a} = {x^{b/2}}{z^{b/2}} = {z^c}$,then $a, b, c$ are in