Consider a computer system in which a hit in cache takes 5 ns. If there is a miss in the cache word is either found in main memory or secondary storage device. If it is found in main memory the access time 100 ns and access time of secondary storage device is 1 μs. If 80% of the time, there is a hit in cache while miss in cache 90% a word within main memory. The average access time in nano second is _____.