Question

A clock is set right at $5$ a.m. The clock loses $16$ min. in $24$ hours. What will be the true time when the clock indicates $10$ p.m. on the $4$th day?

• A. $11$ p.m.
• B. $10$ p.m.
• C. $9$ p.m.
• D. $8$ p.m.

Answer 1

The correct option is A $11$ p.m.

Time from $5$ a.m. on a day to $10$ p.m. on the $4$th day is $89$ hours.
Now, $23$ hrs $44$ min of this clock are the same as $24$ hours of the correct clock.
i.e. $\frac{356}{15}$ hrs. of this clock $=24$ hrs of correct clock.
$\therefore 89$ hrs of this clock =$(\frac{24\times 15}{356}\times 89)$ hrs. of correct clock $=90$ hrs of correct clock.
So, the correct time is $11$ p.m.