Question

Choose the most appropriate option.
A clock was set correct at $12$O' clock. It loses $10$ minutes per hour. What will be the angle between the hour and minute hands of the clock after one hour?

• A. ${90}^0$
• B. ${85}^0$
• C. ${75}^0$
• D. ${105}^0$.

Answer 1

Answer: (B)

${85}^0$

The clock loses $10$ minutes per hour.

Here, the clock shows only $50$ minutes for $60$ minutes ( in $1$ hour )

The clock show the time $12:50$, after $1$ hour.

We can find the angle between hour hand and minutes at $H$ hours $M$ minutes $=30H-\frac{11}{2}M$

The angle between the two hands of the clock after $1$ hour $=30\times 12-\frac{11}{2}\times 50$

$={360}^o-11\times 12$

$={360}^o-{275}^o$

$={85}^o$