Question

At which of the times shown in the options, the hour hand and the minute hand of your clock will be perpendicular to each other?

• A. 09:00
• B. 06:15
• C. 03:45
• D. Both A & B

Answer 1

Answer: (A), (C)

The correct options are
A

09:00

C

03:45

At $09:00$ and $03:00$, hour hand and minute hand are at right angles to each other. Whereas at $6:15$, we see that minute hand will be exactly at $3$ but hour hand will not remain at $6$. As it was at $6$ when the minute hand was at $12$. And since then, minute hand has moved (a quarter of round) which would cause hour hand to move too. So, the angle will not be ${90}^{\circ }$ in that case.