Question

At what time given do the minute and hour hands of a clock make a right angle?

• A. $12$ O'clock
• B. Quarter to $9$
• C. Half past $9$
• D. $3$ O' clock

Answer 1

The correct option is D $3$ O' clock

Option A: At $12$, the angle made by both the hands is $0^o$

Option B: At Quarter to $9$, the angle made by both the hands is very less than ${90}^o$

Option C: At Half past $9$, the angle made by both the hands is more than ${90}^o$

OptionD: At $3$, the angle made by both the hands is perfect ${90}^o$.
Hence option D is the correct answer.