12 A display of lights contains three different colours of bulbs: red, blue and white. There are equal numbers of each colour of bulb. The amount of time that the bulbs stay on can be varied. However, the bulbs always come on according to the following pattern: red bulbs come on every 2 seconds; blue bulbs come on every 3 seconds; white bulbs come on every 5 seconds. Initially, the display is set so that all the bulbs flash momentarily when they come on. All the bulbs flash at the same time at 12:00. (a) How many more times will all the bulbs flash at the same time before 12:05? [2] ​