The image of an object by a mirror is real, inverted and is of magnification -1. If the image is at a distance of 40cm from the mirror where is the object placed? Where would the image be if the object is moved 20cm towards the mirror. Draw ray diagram for the new position of the object.

Consider a production line with five stations. station 1 can produce a unit in 9 minutes. station 2 can produce a unit in 10 minutes. station 3 has two identical machines, each of which can process a unit in 12 minutes (each unit only needs to be processed on one of the two machines. station 4 can produce a unit in 5 minutes. station 5 can produce a unit in 8 minutes. which station is the bottleneck station?