Question

If the hands of a clock show 5:15,what time will its image in a plane mirror show?

Answer 1

It will shows 7:45
hope it may help you

Answer 2

If the clock Has only dots in Time , then on 5:15 you will find it is 7:45

Easier process to remember :
devide the mirror vertically and you will measure the difference between 12 and given time
Then add it from 12 from another side and you will get the time

Very Easy process.