Question

A watch which gains
5
seconds
in
3
minutes
was
set
right at 9 a.m. In the
evening of the same
day, when the watch
indicated quarter
past 6 o'clock, the
true time is:​

Answer 1

Answer:

past 3 minutes

Time from 7 a.m. to 4:15 p.m. = 9 hrs 15 min. = $$\frac{{37}}{4}$$ hrs

3 min. 5 sec. of this c;ocl = 3 min. of the correct clock

⇒ $$\frac{{37}}{{720}}$$ hrs. of this clock = $$\frac{1}{{20}}$$ hrs of the correct clock

⇒ $$\frac{{37}}{4}$$ hrs. of this clock = $$\left( {\frac{1}{{20}} \times \frac{{720}}{{37}} \times \frac{{37}}{4}} \right)$$ hrs. of the correct clock

= 9 hrs. of the correct clock

∴ The correct time is 9 hrs. after 7 a.m. i.e., 4 p.m.