Which type of chromosome is represented by the given figure?

$C-C$ bond length is maximum in

If $f(x) = \frac{1}{x^2} \int_3^x (2t - 3f'(t)) dt$,then $f'(3)$ is equal to

In which aspect does the $Pulmonary \text{ } Artery$ differ from the $Pulmonary \text{ } Vein$?

$A$ father with $8$ children takes them $3$ at a time to the Zoological gardens,as often as he can without taking the same $3$ children together more than once. The number of times he will go to the garden is

The oxide,which cannot act as a reducing agent,is