A computer has a single cache $($off$-$chip$)$ with a $2$ ns hit time and a $98\%$ hit rate. Main memory has a $40$ ns access time. What is the computer$$s effective access time? If we add an on$-$chip cache with a $\mathrm{.}5$ ns hit time and a $94\%$ hit rate, what is the computer$$s effective access time? How much of a speedup does the on$-$chip cache give the computer?