Logarithm of $32\root 5 \of 4 $ to the base $2\sqrt 2 $ is
$3.6$
$5$
$5.6$
None of these
If ${\log _4}5 = a$ and ${\log _5}6 = b,$ then ${\log _3}2$ is equal to
If ${\log _{10}}3 = 0.477$, the number of digits in ${3^{40}}$ is
The sum $\sum \limits_{n=1}^{\infty} \frac{2 n^2+3 n+4}{(2 n) !}$ is equal to :
If ${\log _{10}}x + {\log _{10}}\,y = 2$ then the smallest possible value of $(x + y)$ is
Let $\log _a b=4, \log _c d=2$, where $a, b, c, d$ are natural numbers. Given that $b-d=7$, the value of $c-a$ is