Question 3: (7 marks) (CILO:3) A cold store is controlled by a PLC where four coolers are used C1,C2,C3 and C4. If at least three coolers are working, a green light (G) comes up in the control room. If and only if two coolers are working, an amber light comes on. A red light comes on if neither of the previous conditions is met. 1- Obtain the logic equations which govern the system. 2- Minimize them when it is possible. 3- Realize them using either Siemens S7 PLC or Allen Bradley SCL500