Consider a computer system that has cache memory, main memory (RAM) and disk, and the operating system uses virtual memory. It takes 1 nsec to access a word from the cache, 10 nsec to access a word from the RAM, and 10 ms to access a word from the disk. IF the cache hit rate is 95% and main memory hit rate (after a cache miss) is 99%, what is the average time to access a word?generate answer in ns?