To find Jenny's age as a percentage of her great grandmother's age :

Evans finishes 42 laps in 96,6 mins and Loza finished 38 laps in 102,6 mins
Evans. 96,6÷42= 2,30 mins
Loza . 102,6÷38= 2,70 mins
2,70 mins - 2,30 mins
= 40 secs and Evan is faster with 40secs in each lap.
Answer:
Coordinates switch, and the new y-coordinate changes sign
Explanation:
We have point A with the coordinates (-1,2), when we rotate it c90º it becomes (2,1).
What happened? The coordinates switched and the x-coordinate of A (-1) became the y-coordinate of A' (1) and it changed its sign.