A boy and a girl do the same work in 5 minutes and 10 minutes respectively which of these has more power and why?

Oh, dude, power is just a fancy way of saying how fast you can do work. So, if the boy finishes the work in 5 minutes and the girl takes 10 minutes, obviously the boy has more power because he finishes faster. It's like comparing a sports car to a bicycle, one's just quicker at getting the job done.