From the full moon day counted as day 1, on which day the moon becomes invisible?

Correct option is C

The correct answer is (c) Fifteenth day.
· Starting from a full moon day, the moon goes through its waning phase, gradually reducing visibility each night.
· By the fifteenth day, it reaches the "new moon" phase, making it invisible from Earth.
· This cycle, from full moon to new moon, typically takes about 14-15 days, completing one lunar phase.
Information Booster:
· Lunar Cycle: The cycle of the moon includes phases such as new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, last quarter, and waning crescent.
· New Moon: The phase when the moon is between Earth and the sun, and thus, invisible due to the absence of reflected sunlight.
· Lunar Calendar: Many cultures use the lunar calendar, where each phase, including new and full moons, marks specific days for cultural and religious observances.