If $\frac{1}{{p + q}},\;\frac{1}{{r + p}},\;\frac{1}{{q + r}}$ are in $A.P.$, then
$p,\;,q,\;r$ are in $A.P.$
${p^2},\;{q^2},\;{r^2}$ are in $A.P.$
$\frac{1}{p},\;\frac{1}{q},\;\frac{1}{r}$ are in $A.P.$
None of these
The solution of ${\log _{\sqrt 3 }}x + {\log _{\sqrt[4]{3}}}x + {\log _{\sqrt[6]{3}}}x + ......... + {\log _{\sqrt[{16}]{3}}}x = 36$ is
If $\tan \,n\theta = \tan m\theta $, then the different values of $\theta $ will be in
Let $S_n$ denote the sum of the first $n$ terms of an arithmetic progression. If $\mathrm{S}_{10}=390$ and the ratio of the tenth and the fifth terms is $15: 7$, then $S_{15}-S_5$ is equal to:
After inserting $n$, $A.M.'s$ between $2$ and $38$, the sum of the resulting progression is $200$. The value of $n$ is
Find the sum of integers from $1$ to $100$ that are divisible by $2$ or $5.$