QUESTION 1 [10 marks/ a) Derive logic expressions to design a single-digit BCD counter using D-flip flop that counts and displays in a sequence of 1, 3, 5, 7, 9 and repeat. (5 marks) b) Design an up/down counter to allow a maximum of 12 visitors inside a post-office at a time to ensure that social distancing is being applied for avoiding the spread of Covid-19. Then synthesize a circuit for the counter using T-flip flop