Question

*घंटे और मिनट की सुइयों को एक समकोण बनाने के लिए कितना समय लगता है?*

1️⃣ 60 मिनट
2️⃣ 30 मिनट
3️⃣ 15 मिनट
4️⃣ 25 मिनट​

Answer 1

Given,

A clock with an hour hand and a minute hand.

To find,

How long does it take for the hour and minute hands to make a right angle.

Solution,

Assume that the hour and is made still and the minute hand is movable.

Now in order to make right angles the hand shall make $\[11\]$ revolutions i.e $\[22\]$ times in $\[12\]$ hours right angle shall be made.

Therefore, in a day

$\[\begin{array}{l} \Rightarrow 2 \times 22\\ \Rightarrow 44\end{array}\]$

But in n hour the minute hand makes $\[360^\circ \]$ in $\[60\]$ minutes.

Hence, it takes $\[60\]$minutes for the hour and minute hands to make a right angle.