Mary takes 6.0 seconds to run up a flight of stairs thaf is 102 meters long. if mary wieght is 87 newtons, what power has mary exerted

It really doesn't matter how long the flight of stairs is. What we really need to know is how much height Mary gained, straight up. We don't know that. If we knew the height then the total amount of work she did would be 87 x the height in meters. The unit is joules. Then the power she delivered would be that number divided by the six seconds and that unit is watts. By the way ... it's troubling that Mary's weight is only about 20 pounds. It's doubtful that such a tiny creature could run up a flight of stairs.