If two fair coins are flipped and at least one of the outcomes is known to be a head, what is the probability that both outcomes are heads?

An application loads $$100$$ libraries at startup. Loading each library requires exactly one disk access. The seek time of the disk to random location is given as $$10$$ $$ms$$. Rotational speed of disk is $$6000$$ $$rpm.$$ If all $$100$$ libraries are loaded from random locations on the disk, how long does it take to load all libraries? (The time to transfer data from the disk block once the head has been positioned at the start of the block may be neglected).

Let the time taken to switch between user and kernel modes of execution be $${t_1}$$ while the time taken to switch between two processes be $${t_2}$$.

Which of the following is TRUE?

A Computer handles several interrupt sources of which the following are relevant for this question:

$$ * \,\,\,$$ Interrupt from $$CPU$$ temperature sensor (raises interrupt if $$CPU$$ temperature is too high)

$$ * \,\,\,$$ Interrupt from Mouse (raises interrupt if the mouse is moved or a button is pressed)

$$ * \,\,\,$$ Interrupt from keyboard (raises interrupt when a key is pressed or release)

$$ * \,\,\,$$ Interrupt from Hard Disk (raises interrupt when a disk read is completed)>/p>

Which one these will be handled at the HIGHEST priority?