Final answer:
When it is noon in Mexico, a 90° rotation of Earth, which equals 6 hours of time, would make it 6:00 PM in Mexico.
Step-by-step explanation:
If Mexico is at noon and Earth rotates 90°, we need to calculate the local time in Mexico after this rotation. Knowing that Earth rotates 15° per hour, and thus 90° represents 6 hours of rotation, if it is noon (12:00 PM) before the rotation, 90° later it will be 6:00 PM in Mexico.
This is because Earth rotates from west to east, so as time progresses, each part of the Earth moves into daylight and then away from it as the planet spins.