please explain breifly

Q.2. (10 points) A computer system has a cache (LI). For a given program with 1 million instructions, LI cache miss rate is 20%. Average instruction execution time is 40ns. For all misses, time to take a block from main memory into the LI cache is 600ns. a. Calculate the time to execute this program. Give your result in milliseconds. b. You need to improve the performance of this system. You replace the cache by a new one that is 2 times faster than the existing one, but the new cache has smaller capacity, so the miss rate is increased to 25%. Will the new design improve the performance? Calculate the execution time of the program and prove your