annitaz

Which one of the following is an example of two sets S and T of strings such that S ⊄ T and T ⊄ S, but S* = T*? 1. S = {a, b, abb, bba} and T = {a, b, bba} 2. S = {a, aaaa} and T = {a, aaa, aaaa} 3. S = {a, ab, aab} and T = {a, ab, abab} 4. S = {a, b, aaa} and T = {a, bbb} 5. S = {bb, bbbb} and T = {b} I have excluded answers 1,2,5 but I am stuck with 3 and 4. When is S* equal to T*?

What is the maximum memory locations that can be addressed by a chip with 20 address pins? (1) 20 (2) 262 144 (3) 524 288 (4) 1 048 576 (5) None of the above Can anyone tell me how I can calculate the memory locations? A memory has 1024 storage units with a width of 32. Suppose that the memory is byte addressable. What is the address of the highest addressable memory position? (1) 1023 (2) 1024 (3) 2048 (4) 4096 (5) 4095 Is the correct answer 4095 (1024x4(sets of 8 bits)) =4096-1=4095?? Is that correct?