A given processor requires $1500$ cycles to perform a context switch and star un interrupt handler $($and the same number of cycles to switch bock to the progeram that Was running whien the interrupt occurred$),$ or $500$ cyctes to poll an to device An to device attached to that processor makes $200$ requests per second, each of which takes $12,000$ cycles to resolve once the handler has been started. By default, the processot polls every $0\mathrm{.}4ms$ if it is not using interrupts.

a$.$ How many cycles per second does the processor spend handling $UO$ from the device if interrupts are used?

$(1\mathrm{.}5)$

b$.$ How many cycles per second are spemt on $1/$O if polling is used $($include all polling attempts$)?$ Assume the processor only polls during time slices when user programs are not running, so do not include any context$-$switeh time in your calculation.

$(3)$

c$.$ How often would the processor have to poll for polling to take as many eycles per second as interrupts?