If the ratio of $A.M.$ between two positive real numbers $a$ and $b$ to their $H.M.$ is $m:n$, then $a:b$ is
$\frac{{\sqrt {m - n} + \sqrt n }}{{\sqrt {m - n} - \sqrt n }}$
$\frac{{\sqrt n + \sqrt {m - n} }}{{\sqrt n - \sqrt {m - n} }}$
$\frac{{\sqrt m + \sqrt {m - n} }}{{\sqrt m - \sqrt {m - n} }}$
None of these
If $a$ and $b$ are two different positive real numbers, then which of the following relations is true
Suppose $a,\,b,\,c$ are in $A.P.$ and ${a^2},{b^2},{c^2}$ are in $G.P.$ If $a < b < c$ and $a + b + c = \frac{3}{2}$, then the value of $a$ is
If the $A.M.$ and $G.M.$ of roots of a quadratic equations are $8$ and $5$ respectively, then the quadratic equation will be
Let the sum of an infinite $G.P.$, whose first term is $a$ and the common ratio is $r$, be $5$. Let the sum of its first five terms be $\frac{98}{25}$. Then the sum of the first $21$ terms of an $AP$, whose first term is $10\,ar , n ^{\text {th }}$ term is $a_{n}$ and the common difference is $10{a r^{2}}$, is equal to.
Three positive numbers form an increasing $G.P.$ If the middle term in this $G.P.$ is doubled, the new numbers are in $A.P.$ then the common ratio of the $G.P.$ is: