According to my understanding a decimal numbers to be divided by 8 or 4 its binary should be ended with 000 nd 00 respectively includig null string.(i have considered LSB as a final state of DFA). so minimal DFA for L1 and L2 will consist of 4 and 3 states respectivally,. you can match it also with several binary codes of the numbers divided by 4 or 8..
correct me if I am wrong..