Question

If today in the night sky, we observe a half-illuminated Moon, then after how many days will we be able to observe the same?

• A. $15$ days
• B. $30$ days
• C. $45$ days
• D. $60$ days

Answer 1

Answer: (A), (B), (C), (D)

$60$ days


From the above image, it is clear that every after ($7.5+7.5$)=$15$ days we can see the halfly illuminated moon. This means after $15$ days, $30$ days, $45$ days, and $60$ days, we will see the half-illuminated Moon again.