An eccentric professor used a unique way to measure time for a test lasting 15 minutes. She used just two hourglasses. One measured 7 minutes and the other 11 minutes. During the whole time she turned the hourglasses only 3 times. How did she measure the 15 minutes

When the test began, both hourglasses started to run.

After the 7 minutes  hourglass ran out, she turned it around.

After 4 minutes from then, the 11 minutes  hourglass ran out, and 7 - 4 = 3 minutes are left in the 7 minutes  hourglass. Then she turned around the 7 minutes  hourglass with 7 - 3 = 4 minutes left. Given that 11 minutes had passed, after these 4 minutes, the test is over.

on a coordinate grid, point a is at (−4.0, −2.4) and point b is at (4.0, −2.4). point b is a reflection of point a across the –axis. input either a lowercase x or i think is the right awnser

step-by-step explanation: