Design problems: In all design problems, you should try to reduce the circuit as much as possible, and always make the truth table in the beginning and draw the circuit in the end. 111. Design a logic circuit that will return "logic 0" for odd numbers and return "logic I for even numbers. You are only given 3-bits to perform the above operation. IV. The door to a lab has a combination key pad that takes four entries as either 0's or I's as it's key. To open the door, one needs to enter one of the correct combination keys. Design the key pad system that will open only if the key has two inputs that are 1, such that the two l's occur adjacent to each other. For instance, 1100 is a valid key